Rapid Diagnosis in Ophthalmology Series- Neuro-Ophthalmology-0323044565

Mosby is an affiliate of Elsevier Inc. © 2008, Elsevier Inc. All rights reserved. First published 2008 No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the Publishers. Permissions may be sought directly from Elsevier’s Health Sciences Rights Department, 1600 John F. Kennedy Boulevard, Suite 1800, Philadelphia, PA 19103-2899, USA: phone (+1) 215 239 3804, fax (+1) 215 239 3805, or e-mail [email protected]. You may also complete your request online via the Elsevier homepage (http://www.elsevier.com) by selecting ‘Support and Contact’ and then ‘Copyright and Permission’. ISBN 978-0-323-04456-1 British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging in Publication Data A catalog record for this book is available from the Library of Congress Notice Medical knowledge is constantly changing. Standard safety precautions must be followed, but as new research and clinical experience broaden our knowledge, changes in treatment and drug therapy may become necessary or appropriate. Readers are advised to check the most current product information provided by the manufacturer of each drug to be administered to verify the recommended dose, the method and duration of administration, and contraindications. It is the responsibility of the practitioner, relying on experience and knowledge of the patient, to determine dosages and the best treatment for each individual patient. Neither the Publisher nor the authors assume any liability for any injury and/or damage to persons or property arising from this publication. The Publisher

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Series Preface

This handy pocket sized reference series puts the knowledge of world-renowned experts at your fingertips. The standardized format provides the key element of each disease entity as your first encounter. The additional information on the clinical presentation, ancillary testing, differential diagnosis and treatment, including the prognosis, allows the clinician to instantly diagnose and treat the most common diseases seen in a busy practice. Inclusion of classical clinical color photos provides additional assurance in securing an accurate diagnosis and initiating management.

Rapid Diagnosis in Ophthalmology

Given the complexity and quantity of clinical knowledge required to correctly identify and treat ocular disease, a quick reference text with high quality color images represents an invaluable resource to the busy clinician. Despite the availability of extensive resources online to clinicians, accessing these resources can be time consuming and often requires filtering through unnecessary information. In the exam room, facing a patient with an unfamiliar presentation or complicated medical problem, this series will be an invaluable resource.

Regardless of the area of the world in which the clinician practices, these handy references guides will provide the necessary resources to both diagnose and treat a wide variety of ophthalmic diseases in all ophthalmologic specialties. The clinician who does not have easy access to sub-specialists in Anterior Segment, Glaucoma, Pediatric Ophthalmology, Strabismus, Neuro-ophthalmology, Retina, Oculoplastic and Reconstructive Surgery, and Uveitis will find these texts provide an excellent substitute. World-wide recognized experts equip the clinician with the elements needed to accurately diagnose treat and manage these complicated diseases, with confidence aided by the excellent color photos and knowledge of the prognosis. The field of knowledge continues to expand for both the clinician in training and in practice. As a result we find it a challenge to stay up to date in the diagnosis and management of every disease entity that we face in a busy clinical practice. This series is written by an international group of experts who provide a clear, structured format with excellent photos. It is our hope that with the aid of these six volumes, the clinician will be better equipped to diagnose and treat the diseases that affect their patients, and improve their lives. Marian S. Macsai and Jay S. Duker

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This is neuro-ophthalmology in a shot glass - short but potent. It is all here in concentrated form - the manifestations, the disease mechanisms, the pitfalls, the practical guidelines, and the pictures.

Preface

If your patient has a visual problem or funny eye movements and you cannot quite figure out what is going on, chances are the problem falls within the domain of neuro-ophthalmology.

The text is bulleted for easy grasp. The fundus photographs are my best-in-show from material extending back over 40 years of clinical practice. The brain imaging illustrations are prepared to highlight the lesions. Eye movement and alignment abnormalities are a challenge to illustrate without videos; I have chosen to present schematic illustrations because still photographs so rarely tell the story properly. I hope that you will find this book useful and that it will make you wonder at the marvels of the nervous system. Jonathan D. Trobe

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Section 1 Transient Visual Loss Transient Monocular Visual Loss (Amaurosis Fugax)

2

Transient Binocular Visual Loss

4

Migraine with Typical Visual Aura

6

Retinal Migraine (Presumed Retinal Vasospasm)

8

Transient Monocular Visual Loss (Amaurosis Fugax*) Key Facts Abrupt visual loss affecting one eye that lasts <60 min Sometimes associated with scintillations (photopsias, positive visual phenomena) Caused by reduced perfusion of eye (ocular transient ischemic attack, TIA) Common causes: • cervical carotid stenosis • systemic hypotension • idiopathic (possible retinal artery vasospasm) • impending retinal or optic nerve infarction • papilledema • Evidence that carotid endarterectomy benefits patients suffering only ocular TIA is weak

• • • •

Clinical Findings • Eye examination is usually normal but may show intra-arterial retinal platelet– fibrin–cholesterol (Hollenhorst) plaque, optic disc edema, or venous stasis retinopathy

SECTION 1 • Transient Visual Loss

Ancillary Testing • Carotid ultrasound, CT angiography, or magnetic resonance angiography to rule out stenosis, dissection, and dysplasia • Blood pressure (including orthostatic) testing to rule out hypertension or hypotension • Electrocardiography to rule out atrial fibrillation • Cardiac echography to rule out cardioembolic source • Blood tests to rule out hypercoagulable state: • complete blood count • serum protein electrophoresis • prothrombin and partial thromboplastin times • antiphospholipid antibodies • antithrombin-3 • factor V Leiden • prothrombin gene mutation • homocysteine • sickle hemoglobin • serum viscosity

Differential Diagnosis • • • • • • •

Embolism from cervical carotid artery, aortic arch, or cardiac valve or wall Systemic hypertension or hypotension Hypercoagulable state Impending retinal vascular occlusion Ischemic oculopathy Retinal vasospasm (see Retinal migraine) Papilledema

Treatment • Direct at underlying condition • Endarterectomy often advocated for >70% ipsilateral cervical carotid stenosis, but evidence of benefit for purely ocular TIA is weak • Reduce modifiable arteriosclerotic risk factors (diabetes, hypertension, dyslipidemia, lack of exercise, obesity, cigarette smoking) • Correct very high blood pressure but avoid excessive blood pressure lowering (may lead to perfusion failure and stroke of eyes or brain) • Aspirin 81 mg/day for underlying arteriosclerosis

Prognosis • Depends on underlying condition 2

*Amaurosis fugax is an old term that is out of favor because it does not specify whether transient visual loss is monocular or binocular

Fig. 1.2 Cervical carotid stenosis. The critical narrowing of the proximal internal carotid artery (arrow) is the result of arteriosclerosis. This lesion probably gave rise to the Hollenhorst plaque in Fig. 1.1.

Transient Monocular Visual Loss (Amaurosis Fugax)

Fig. 1.1 Hollenhorst plaque. The refractile yellow dot (arrow) is an impacted platelet–fibrin embolus that traveled from the ipsilateral common carotid artery bifurcation in the neck. It produced transient visual loss by causing ischemia to the retina. Caution: most patients with transient monocular visual loss have no abnormalities on fundus examination.

3

Transient Binocular Visual Loss Key Facts • Abrupt visual loss affecting both eyes and lasting <60 min • Caused by dysfunction of visual cortex or optic nerves in both eyes • Common causes: • migraine • visual cortex transient ischemic attack (TIA) • visual cortex seizure • papilledema

Clinical Findings


• Migraine: scintillations (often with zigzag border) that march across one hemifield and last 20–30 min; headache may follow • TIA: homonymous or total visual loss lasting minutes that may have scintillations; headache is rare • Focal seizure: stationary, often colored visual scintillations lasting seconds to minutes; persistent homonymous hemianopia sometimes • Papilledema: blackouts of vision lasting seconds, often precipitated by upright posture

Ancillary Testing • If suspecting TIA: • echocardiography or vascular imaging may show source of emboli • cardiac telemetry may show atrial fibrillation • blood pressure testing may show hypertension or hypotension • If suspecting focal seizure: • brain imaging may show mass, encephalomalacia, enhancing meninges • electroencephalography may show epileptic focus

Treatment • Migraine: usually no treatment unless headaches are frequent and debilitating • If so, treat with standard prophylactic agents (beta blockers, calcium channel blockers, valproic acid, topiramate, aspirin) • Visual cortex TIA: • warfarin if cardiogenic emboli, otherwise aspirin 81 mg/day or clopidogrel 75 mg/day • correct discretionary arteriosclerotic risk factors • Visual cortex seizure: treat underlying lesion if possible, anticonvulsants • Papilledema: treat underlying cause

Prognosis • Depends on underlying condition

4

Transient Binocular Visual Loss

Fig. 1.3 Epileptogenic occipital mass. Postcontrast axial T1 MRI shows left occipital mass (arrow) that proved on resection to be metastatic breast cancer. It provoked seizures manifested by transient binocular sparkling (scintillations) in the right hemifield and a partial right homonymous hemianopia.

5

Migraine with Typical Visual Aura Key Facts • Episodic neuronal discharge starting in brainstem and ending in visual cortex • Usually no underlying disease (primary headache disorder) • Typical visual aura (hallucination) is a bright (scintillating) scotoma with zigzag (fortification) border that traverses the hemifield in 20–30 min • Headache, photophobia, or sonophobia may follow aura and last ≤48 h • Visual aura may occur without headache (acephalgic migraine, dissociated migraine), especially in older adults • First attack usually occurs before age 30 but may occur much later

Clinical Findings • Visual fields may show homonymous hemianopia during the aura • No ophthalmic abnormalities after aura has dissipated • Diagnosis based entirely on history

Ancillary Testing


• Brain imaging necessary only if visual fields are abnormal, patient has other neurologic manifestations, or symptoms are atypical of migraine

Differential Diagnosis • • • •

Visual cortex transient ischemic attack Visual cortex seizure Papilledema Migrainous event secondary to underlying cerebral pathology (mitochondrial disorders, lupus erythematosus, occipital lobe arteriovenous malformations, and cerebral autosomal dominant arteriopathy with strokes and leukoencephalopathy [CADASIL])

Treatment • Eliminate precipitating factors if possible • Prescribe migraine prophylactic agents (beta blockers, calcium channel blockers, topiramate, valproic acid, aspirin) if attacks are frequent and debilitating • Prescribe migraine abortive agents (triptans) if non-visual symptoms are debilitating • Advise patient to discontinue smoking and contraceptive medication because they increase risk of stroke

Prognosis • Abortive agents have no effect on visual aura but usually attenuate non-visual symptoms • Prophylactic agents usually reduce attack frequency and intensity • Risk of stroke is small but not negligible if patient is a smoker or uses oral contraceptive medication

6

A

B

C

D

Migraine with Typical Visual Aura

Fig. 1.4 The scintillating scotoma of migraine. A sparkling (scintillating) blur spot appears next to fixation in both eyes (A) and enlarges across the hemifield, with a zigzag border at its leading edge (B). It encompasses the hemifield within 20– 30 min (C) and then disappears (D). This is the most typical visual aura of migraine.

7

Retinal Migraine (Presumed Retinal Vasospasm*) Key Facts • • • • • •

Transient monocular visual loss in a young patient No other symptoms during episode May have history of migraine Normal ophthalmologic examination No risk factors for arteriosclerosis or evidence of embolic source Attributed presumptively to retinal vasospasm after reasonable exclusion of other causes

Clinical Findings • May see retinal arterial focal constriction during attack

Ancillary Testing

SECTION 1 • Transient Visual Loss 8

• All studies for an alternative cause of transient monocular visual loss are negative (see Transient monocular visual loss [amaurosis fugax])

Differential Diagnosis • • • • •

Carotid stenosis Systemic hypotension Hypercoagulable or hyperviscous state Impending retinal artery, retinal vein, or ciliary (optic nerve) occlusion Papilledema

Treatment • Calcium channel blockers (verapamil 120–360 mg/day) for patients with frequent disabling recurrent attacks

Prognosis • Calcium channel blockers may reduce attack frequency • Permanent visual loss from stroke is rare • Episodes often spontaneously remit in time

*Not a term in general use but preferred over retinal migraine because the physiology of migraine, spreading neuronal depression, has never been shown experimentally in the retina. More likely, the visual loss is caused by retinal vasospasm, but this can rarely be proved unless the constricted vessels are seen ophthalmoscopically during the event.

A

B

Retinal Migraine (Presumed Retinal Vasospasm)

Fig. 1.5 (A) Fundus photograph of a patient during an episode of visual loss in the right eye shows constriction of the central (arrowheads) and peripheral (arrows) arterial branches. (B) When vision returned to normal, the fundus arteries and veins had returned to normal caliber. (After Burger SK et al. N Engl J Med 1991; 325:870–873, with permission.)

9

Section 2 Congenital Optic Nerve Disorders Congenitally Elevated Optic Disc

12

Optic Disc Coloboma

14

Optic Pit

16

Morning Glory Optic Disc Anomaly

18

Optic Disc Hypoplasia

20

Congenitally Elevated Optic Disc Key Facts • Monocular or binocular congenital crowding of the optic disc with: • indistinct margins • dome-shaped elevation • absent physiologic cup • sometimes obvious drusen • Often confused with acquired optic disc elevation, especially papilledema (hence the term pseudopapilledema) • Visual field defects may enlarge but visual acuity remains normal

Clinical Findings • • • •

SECTION 2 • Congenital Optic Nerve Disorders 12

Indistinct optic disc margins, dome-shaped elevation, and absent physiologic cup Disc vessels often have excessive tortuosity, trifurcations, or abnormal take-off Optic disc drusen may be evident Nerve fiber bundle visual field defects may be present • they may slowly enlarge but do not impair visual acuity • May be difficult to distinguish from acquired optic disc edema (especially papilledema) on ophthalmoscopic grounds alone

Ancillary Testing • Red-free fundus photography, B-scan ultrasound, or orbit CT often shows occult optic disc drusen • Late phase fluorescein angiography shows no dye leakage


Papilledema Diabetic papillopathy Compressive optic neuropathy Pre-eruptive anterior ischemic optic neuropathy

Treatment • None • Retest visual fields periodically to assess whether defects are present or enlarging to the point of impairing safe driving or other visually demanding occupational tasks

Prognosis • Visual field loss may become severe but visual acuity remains normal

Fig. 2.1 Congenitally elevated optic discs. Telling the difference between this condition and acquired optic disc elevation, especially papilledema, may be difficult! That is why this condition is often called pseudopapilledema.

Fig. 2.3 CT scan shows the drusen as bright (high attenuation) dots in the optic discs.

Congenitally Elevated Optic Disc

Fig. 2.2 Congenitally elevated optic disc with drusen. These refractile particles reflect optic nerve axoplasmic stasis of congenital origin. Visual field loss is often present and may be slowly progressive.

13

Optic Disc Coloboma Key Facts • Congenital inferotemporal absence of optic disc tissue as the result of faulty closure of fetal fissure • Retinochoroidal, iris, or eyelid coloboma may also be present • Corresponding deep, steep-margined, stationary nerve fiber bundle visual field defect • May have forebrain anomalies, especially basal encephalocele

Clinical Findings


• Fissure-like absence of inferotemporal neuroretinal rim tissue, with distinct margins that may extend beyond the disc margin to involve retinochoroidal tissue • Iris and lid colobomas sometimes present • Corresponding steep-margined, non-progressive dense nerve fiber bundle visual field defect • If papillomacular bundle is involved, acuity may be markedly depressed • Sometimes forebrain anomalies, especially basal encephalocele

Ancillary Testing • Brain imaging may show forebrain anomalies

Differential Diagnosis • Glaucoma • Chorioretinal scar

Treatment • Neurosurgery may be indicated to treat basal encephalocele

Prognosis • Visual field loss is stationary

Optic Disc Coloboma

Fig. 2.4 Optic disc coloboma. Optic disc shows total congenital excavation, the result of incomplete closure of the fetal fissure.

Fig. 2.5 Iris coloboma (arrow) in an eye that also had an optic disc and retinal coloboma in the same region! These are manifestations of the same embryonic defect.

15

Optic Pit Key Facts • Congenital excavation in the neuroretinal rim caused by absence of axons • Nearly always associated with a corresponding steep-margined nerve fiber bundle visual field defect • Serous retinal detachment and/or retinoschisis of the macula may occur • Uncommonly associated with other developmental brain anomalies

Clinical Findings • Inferotemporal round excavation in neuroretinal rim small enough to be overlooked • Corresponding steep-margined nerve fiber bundle defect • Sometimes serous detachment of macula

Ancillary Testing


• If fovea detachment present, optical coherence tomography shows subretinal fluid and retinoschisis

Differential Diagnosis • Coloboma • Glaucoma

Treatment • If macular serous detachment is present, photocoagulation or vitrectomy

Prognosis • Visual field loss is stationary • Serous detachment is often difficult to treat

Optic Pit

Fig. 2.6 Optic pit. Optic disc shows scalloped excavation inferotemporally, probably a forme fruste of coloboma.

Fig. 2.7 Serous retinal detachment (arrowheads) in a patient with an optic pit (arrow). (Courtesy of Mark W. Johnson, MD.)

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Morning Glory Optic Disc Anomaly Key Facts • Enlarged, totally excavated optic disc with: • surface glial veils • spoke-like retinal vessels emerging from its edge • peripapillary retinochoroidal atrophy with pigment alteration • Forebrain anomalies often present

Clinical Findings

SECTION 2 • Congenital Optic Nerve Disorders

• Staphyloma of posterior pole, excavation of an enlarged optic disc with surface glial veils, spoke-like retinal vessels emerging from its edge, and peripapillary retinochoroidal atrophy with pigment alteration • Nearly always uniocular • Visual function usually poor in affected eye • Sometimes forebrain anomalies, including: • basal encephalocele • callosal dysgenesis • hypoplastic intracranial carotid arteries with prominent basal cranial anastomoses (moya moya disease) • hypopituitarism


Optic disc coloboma Staphyloma Myopic degeneration Healed chorioretinitis

Ancillary Testing • Brain imaging may disclose forebrain abnormalities • Endocrine testing may disclose hypopituitarism, especially if there are forebrain abnormalities

Treatment • Directed at associated findings • Correction of hypopituitarism, especially low corticoid and growth hormones, is critical

Prognosis • Visual deficit is usually severe but stable

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Fig. 2.9 Midline brain malformations. Precontrast sagittal T1 MRI shows enlarged cisterna magna, hypoplastic cerebellar vermis, small optic chiasm, and malformed occipital lobes. The patient also had a tethered spinal cord. These are all midline dysgenetic abnormalities associated with morning glory optic disc anomaly.

Morning Glory Optic Disc Anomaly

Fig. 2.8 Morning glory optic disc anomaly, right eye. The optic disc is enlarged and excavated with radially exiting vessels, surface gliosis, and peripapillary atrophy.

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Optic Disc Hypoplasia Key Facts • Small optic disc (and nerve) owing to reduced number of axons • Degree of visual deficit variable • Subtle hypoplasia may be hard to detect on ophthalmoscopy (characteristic double-ring sign present in <50% of cases) • Forebrain anomalies more likely if optic disc hypoplasia is bilateral • Superior segmental hypoplasia variant associated with maternal diabetes

Clinical Findings • Small diameter disc substance usually accompanied by peripapillary atrophy • outer margin of disc and outer margin of peripapillary atrophy may be slightly pigmented, giving rise to double-ring sign • If hypoplasia is minimal and there is no double-ring sign, may be difficult to recognize ophthalmoscopically (compare area occupied by vessels with diameter of disc)

SECTION 2 • Congenital Optic Nerve Disorders

Ancillary Testing • Brain imaging may show forebrain anomalies, including absence of septum pellucidum and hypoplasia of corpus callosum (de Morsier syndrome) • T1 MRI posterior pituitary bright spot may be absent or displaced upward into tuber cinereum • If so, growth and adrenocorticotropic hormones may be deficient • Monitor growth and development and assess hormone levels

Differential Diagnosis • Small but normal optic disc

Treatment • Directed at associated brain anomalies and hormone deficiencies

Prognosis • Visual dysfunction stable and very difficult to assess in infancy

Fig. 2.10 Bilateral severe optic disc hypoplasia in an infant with multiple midline cerebral defects.

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Fig. 2.11 Left optic disc hypoplasia. Note the double-ring sign based on the cuff of peripapillary retinochoroidal atrophy (arrows). Compare with the normal optic disc in the right eye.

Optic Disc Hypoplasia

Fig. 2.12 Retrobulbar imaging of hypoplastic right optic nerve. Postcontrast coronal T1 MRI shows that the right optic nerve (arrow) has a smaller diameter than the left optic nerve.

Fig. 2.13 Superior segmental optic disc hypoplasia in a patient born of a diabetic mother. Note the take-off of the superior optic disc vessels close to the disc margin. The patient had corresponding inferior arcuate visual field defects.

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Section 3 Acquired Optic Nerve or Chiasm Disorders

Typical Optic Neuritis Atypical Optic Neuritis Papillitis (Neuroretinitis) Non-arteritic Anterior Ischemic Optic Neuropathy Arteritic Anterior Ischemic Optic Neuropathy Posterior Ischemic Optic Neuropathy Hypotensive Ischemic Optic Neuropathy Toxic Optic Neuropathy Nutritional Deficiency Optic Neuropathy Dominantly Inherited Optic Neuropathy Leber Hereditary Optic Neuropathy Compressive Optic Neuropathy and Chiasmopathy Sphenoid Meningioma Optic Nerve Sheath Meningioma Craniopharyngioma Pituitary Adenoma Optic Glioma (Pilocytic Astrocytoma of Optic Nerves or Chiasm) Anterior Visual Pathway Intracranial Aneurysm Traumatic Optic Neuropathy Radiation Optic Neuropathy Graves Optic Neuropathy Papilledema Idiopathic Intracranial Hypertension (Pseudotumor Cerebri) Hypertensive Optic Neuropathy Infiltrative (Neoplastic) Optic Neuropathy Paraneoplastic Optic Neuropathy Diabetic Papillopathy

24 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 72 76 78 80 82

Typical Optic Neuritis Key Facts • Acute or subacute monocular visual loss caused by primary demyelination of the optic nerve • Isolated idiopathic condition or part of multiple sclerosis (MS) • Afferent pupil defect often the only objective finding • >75% of patients show enhancement of affected optic nerve on T1 fat-suppressed MRI • Spontaneous near total recovery of visual function within 6 months in >85% • No treatment improves on long-term spontaneous recovery of visual function

Clinical Findings

SECTION 3 • Acquired Optic Nerve or Chiasm Disorders

• Acute or subacute visual loss often accompanied by ipsilateral periocular pain exacerbated by eye movement • Reduced visual acuity or nerve fiber bundle visual field defects in affected eye • Afferent pupil defect in affected eye (unless fellow eye has equivalent optic nerve damage) • Optic disc appears normal (60%) or only mildly swollen • May have symptoms, signs, or previous diagnosis of MS • No other clinical manifestations except those attributable to MS

Ancillary Testing • MRI: enhancement of affected optic nerve in >75%, cerebral white matter signal abnormalities typical of MS in 50% (high-risk MRI) • Visual evoked potentials: prolonged latencies in affected (and sometimes fellow) eye • Lumbar puncture: elevated immunoglobulins and/or oligoclonal bands in 25%

Fig. 3.1 Optic neuritis, right eye. Mild optic disc swelling and hyperemia are evident. Caution: many patients with typical optic neuritis show no abnormalities on fundus examination!

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Fig. 3.2 Orbit MRI in left optic neuritis. Postcontrast, fatsuppressed T1 (A) posterior orbital and (B) canalicular coronal studies and (C) axial study show enhancement of the left optic nerve (arrows).

A

Typical Optic Neuritis

B

C

25

Typical Optic Neuritis (Continued) Differential Diagnosis • • • • • •

Atypical optic neuritis Ischemic optic neuropathy Compressive optic neuropathy Infiltrative (neoplastic) optic neuropathy Leber hereditary optic neuropathy Paraneoplastic optic neuropathy

Treatment

SECTION 3 • Acquired Optic Nerve or Chiasm Disorders 26

• Patients with high-risk MRI: intravenous methylprednisolone 1 g/day for 3 days followed by prednisone 1 mg/kg for 11 days, administered within 1 week of onset, significantly reduces likelihood of developing MS during next 2 years but not thereafter • In patients with high-risk MRI, treatment with interferon beta or glatiramer acetate reduces accumulation of MRI signal abnormalities and clinical relapses but there is no solid evidence that this regimen improves long-term disability from MS • In patients with MRI white matter signal abnormalities (high-risk MRI), intravenous and oral methylprednisolone regimen reduces chances of developing MS during next 2 years but does not alter long-term chances of developing MS

Prognosis • Spontaneous near total recovery of vision in >85% within 6 months • 30% get recurrent optic neuritis in previously affected or fellow eye within 5 years • 40% of patients develop MS within 10 years • Abnormal white matter signal on MRI at onset of first-attack optic neuritis triples likelihood of developing MS

Fig. 3.3 Brain MRI in optic neuritis. Axial FLAIR MRI shows scattered high-signal abnormalities lateral and perpendicular to the ventricular borders. Sometimes called Dawson fingers, these lesions represent demyelination along periependymal veins.

Typical Optic Neuritis (continued) 27

Atypical Optic Neuritis Key Facts • Visual loss from secondary demyelination of optic nerve • Common causes: • sarcoidosis • non–multiple sclerosis (MS) autoimmune disorders • uveitis • infectious retinitis and meningitis • idiopathic disorders • Diagnosed by clinical and/or imaging features consistent with a systemic disorder and not consistent with MS • Unlike typical optic neuritis, visual loss often improves with corticosteroid treatment (corticosteroid-responsive) and worsens when corticosteroids are tapered or withdrawn (corticosteroid-dependent)

Clinical Findings


• Reduced visual acuity or nerve fiber bundle visual field defects • Afferent pupil defect (unless both eyes equally affected) • Fundus may be normal or show: • optic disc swelling • signs of posterior uveitis (choroidal infiltrates, vitreous cells) • retinopathy (infiltrates, serous detachment, macular star exudates) • Anterior uveitis may be present • Systemic features of sarcoidosis, infection, or autoimmune disorders • Continued progression of visual loss for >2 weeks

Ancillary Testing • Imaging, lumbar puncture, blood or urine tests show signs either inconsistent with MS or consistent with another disease

Differential Diagnosis • • • • • •

Typical optic neuritis Ischemic optic neuropathy Compressive optic neuropathy Infiltrative (neoplastic) optic neuropathy Leber hereditary optic neuropathy Paraneoplastic optic neuropathy

Treatment • Non-specific: corticosteroids and corticosteroid-sparing immunomodulatory agents • Specific: directed at underlying disease • Prolonged treatment often necessary • Dose tapering must be gradual to prevent recrudescences

Prognosis • Depends on underlying disease and on whether axonal damage has occurred (the worse the axonal damage, the less the recovery)

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Atypical Optic Neuritis

Fig. 3.4 Swollen left optic disc and peripapillary retina with choroidal infiltrates in a patient with sarcoidosis. Caution: most patients with sarcoidosis affecting the optic nerves show no fundus abnormalities!

A

B

Fig. 3.5 Brain MRI in neurosarcoidosis. (A) Precontrast coronal T1 MRIs show thickening (arrows) of the optic nerves (left) and hypothalamus (right). (B) Postcontrast studies show that the thickened areas enhance (arrows).

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Papillitis (Neuroretinitis*) Key Facts • A form of optic neuritis in which the optic disc is swollen and sometimes there are disc surface hemorrhages and perifoveal hard exudates (macular star figure) • Common causes: • idiopathic • cat scratch disease • syphilis • Lyme disease • toxoplasmosis • Brain and orbit imaging usually not contributory • In idiopathic cases, treatment with corticosteroids or other immunosuppressive agents probably does not alter clinical course

Clinical Findings


• Acute uniocular visual loss sometimes accompanied by ipsilateral periocular pain exacerbated by eye movement • Reduced visual acuity and/or nerve fiber bundle visual field defect • Afferent pupil defect • Optic disc swelling, often florid, sometimes with disc surface hemorrhages • Perifoveal hard exudates (macular star figure) typically become prominent only as disc swelling is disappearing • Sometimes accompanied by vitritis or retinal perivascular cuffing (vasculitis) • Usually an isolated clinical manifestation

Ancillary Testing • Laboratory studies usually negative, but in atypical cases there are abnormalities in: • blood count • electrolytes • hepatic, renal, or coagulation profile • acute phase reactants • chest x-ray • syphilis, Bartonella, Lyme, or toxoplasmosis serologies • MRI may show thickening and/or enhancement of affected orbital segment of optic nerve and/or its sheath

Differential Diagnosis • • • • • • • •

Ischemic optic neuropathy Leber hereditary optic neuropathy Infiltrative optic neuropathy Hypertensive optic neuropathy Diabetic papillopathy Papilledema Central retinal vein occlusion Paraneoplastic optic neuropathy

Treatment • Corticosteroids (dose depends on diagnosis and severity of visual loss) • Corticosteroid-sparing agents (mycophenolate, cyclosporine, methotrexate, azathioprine, tumor necrosis factor inhibitors) may be used if patient is corticosteroid-intolerant or requires chronic intensive therapy • Antibiotics for infection, if present

Prognosis • Depends on underlying condition • Early treatment tends to be most effective in preventing visual loss

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*Neuroretinitis is a term used to signify that the optic disc and retina are both inflamed, but the process originates in the optic nerve, so papillitis is a better term.

Fig. 3.6 Papillitis, left eye. Swollen optic disc with cotton wool spots and hemorrhages, perivascular sheathing, and swollen peripapillary retina.

Fig. 3.8 Papillophlebitis, left eye. Optic disc is swollen with hemorrhages and cotton wool spots, retina shows posterior pole edema, and there is widespread venous engorgement and hemorrhage. This combination of findings is often called papillophlebitis in the belief that inflammation of the optic disc is primary and that inflammation and obstruction of the retinal veins is secondary.

Papillitis (Neuroretinitis)

Fig. 3.7 Macular star figure in resolving papillitis, left eye. There is a ring of hard exudates around the fovea.

31

Non-arteritic Anterior Ischemic Optic Neuropathy Key Facts • Acute painless monocular visual loss in a patient aged >40 years caused by impaired perfusion of the optic nerve • Optic disc edema must be present in affected eye • No other clinical manifestations • Arteriosclerotic risk factors should be present: • hypertension • diabetes • smoking • dyslipidemia • obesity • family history of premature arteriosclerosis • No symptoms to suggest polymyalgia rheumatica or temporal arteritis • Sometimes follows exuberant use of systemic antihypertensive agents to lower blood pressure • Little if any recovery of vision • No effective treatment


Clinical Findings • Acute and painless monocular visual loss • Reduced visual acuity and/or visual field (nerve fiber bundle defect) in affected eye • Swollen optic disc (may be subtle) in affected eye, that is often segmental, pallid, and studded with papillary hemorrhages • Optic discs in both eyes lack physiologic cups (discs at risk, little red discs) • No symptoms of polymyalgia rheumatica or giant cell arteritis

Ancillary Testing • • • •

Blood pressure may be abnormally high or low Acute phase reactants (sedimentation rate, C-reactive protein) are normal Blood sugar or HgA1C may be high Brain and orbit MRI shows no pertinent abnormalities


Atypical optic neuritis Arteritic anterior ischemic optic neuropathy Infiltrative (neoplastic) optic neuropathy Diabetic papillopathy Leber hereditary optic neuropathy Hypertensive optic neuropathy Papilledema Paraneoplastic optic neuropathy

Treatment • Reduce discretionary arteriosclerotic risk factors • Avoid excessive lowering of blood pressure

Prognosis • Visual loss may progress over 2 weeks • Visual recovery is negligible • 10–15% chance of similar occurrence in fellow eye over 10 years • No evidence that any measure reduces this risk

32

Non-arteritic Anterior Ischemic Optic Neuropathy

Fig. 3.9 Non-arteritic ischemic optic neuropathy. Optic disc is segmentally swollen with hemorrhage.

33

Arteritic Anterior Ischemic Optic Neuropathy Key Facts


• Sudden, often devastating, visual loss in one eye or both in a patient aged >60 years • Caused by infarction of optic nerve from arteritic occlusion of ophthalmic artery (ciliary) branches • Optic disc edema, often pallid, nearly always present in affected eye • If visual loss affects only one eye, fellow eye will be affected by same process in ≤ 50% within days to weeks if patient is not adequately treated • New headache, scalp tenderness, jaw claudication, fatigue, anorexia, and limb girdle aches often precede visual loss but ophthalmic manifestations may occur without any systemic symptoms • Erythrocyte sedimentation rate and/or C-reactive protein elevated in 80% • Definitive diagnosis depends on temporal artery biopsy showing inflammatory destruction of media–intima junction with or without giant cells • Prompt high-dose corticosteroid treatment does not reverse visual loss but probably reduces chances of second eye involvement

Clinical Findings • • • • •

Painless monocular or binocular visual loss Marked reduction in visual acuity and/or visual field (nerve fiber bundle defects) Optic disc swelling (often pallid) Sometimes cotton wool spots Preceding systemic symptoms of polymyalgia rheumatica (fatigue, anorexia, limb girdle aches) or cephalgia (new headache, scalp tenderness, jaw claudication) in ≥80%

Ancillary Testing • Erythrocyte sedimentation rate and/or C-reactive protein elevated in 80% • >2 cm temporal artery specimen shows inflammatory destruction of media– intima junction with or without giant cells in 96% • Fluorescein angiography often shows choroidal filling defects

Differential Diagnosis • Non-arteritic ischemic optic neuropathy • Atypical optic neuritis • Infiltrative optic neuropathy

Treatment • Start intravenous methylprednisolone 1–2 g/day for 3–5 days followed by prednisone 1.5 mg/kg before obtaining temporal artery biopsy for strong presumptive diagnosis • Discontinue treatment if biopsy is negative (obtain biopsy within 1 week of starting corticosteroid treatment to allow maximum sensitivity in diagnosis) • Taper oral prednisone at rate of 10 mg/week according to systemic symptoms and acute phase reactants, keeping daily dose >10–15 mg/day for ≤1 year

Prognosis • Visual loss irreversible but usually non-progressive in affected eye(s) • Unaffected fellow eye may develop same process despite treatment but rarely after 1 year of adequate treatment 34

Arteritic Anterior Ischemic Optic Neuropathy

Fig. 3.10 Optic disc shows pallid (white) swelling reflecting infarction of disc tissue.

35

Posterior Ischemic Optic Neuropathy Key Facts • Acute visual loss (usually monocular) with features of optic nerve dysfunction • No optic disc edema • Common causes: • previous cranial radiation • intracranial surgery • acute systemic hypotension • herpes zoster or sino-orbital fungal infection • systemic vasculitis (Wegener granulomatosis, giant cell arteritis, lupus erythematosus, relapsing polychondritis, polyarteritis nodosa) • Almost never occurs without a discoverable predisposing condition

Clinical Findings


• • • • •

Acute (usually monocular) painless loss of visual acuity and/or visual field Nerve fiber bundle visual field loss Afferent pupil defect Normal optic disc Usually there is evidence of a predisposing cause: • episode of systemic hypotension • previous cranial radiation • intracranial surgery • trigeminal zoster • known systemic vasculitis

Ancillary Testing • Brain and orbit imaging may show enhancement of optic nerve and/or sino-orbital masses • Laboratory tests to rule out: • Wegener granulomatosis • giant cell arteritis • lupus erythematosus • relapsing polychondritis • polyarteritis nodosa


Optic neuritis Compressive optic neuropathy Leber hereditary optic neuropathy Hypotensive optic neuropathy Infiltrative (neoplastic) optic neuropathy Paraneoplastic optic neuropathy

Treatment • Directed at underlying condition

Prognosis • Visual recovery usually negligible

36

A

Fig. 3.11 (A) Postcontrast axial T1 shows enhancement of the intraconal fat and optic nerve in the right orbit (arrow) in a patient with mucormycosis. (B) Postcontrast coronal T1 shows that the enhancement extends into the right cavernous sinus (arrow).

Posterior Ischemic Optic Neuropathy

B

37

Hypotensive Ischemic Optic Neuropathy Key Facts • Acute monocular or binocular visual loss caused by infarction of optic nerve as the result of systemic hypotension • Most patients have arteriosclerotic risk factors • Cardiac bypass or prolonged lumbar spine surgery most common setting • Systemic hypotension often documented in anesthesia record • Visual loss often not apparent until days after surgery • Optic disc(s) may be swollen or normal at outset • If normal, may swell days later • Affected discs become pale weeks later • Visual recovery is variable • No effective treatment

Clinical Findings • Visual loss reported within days of surgery • Visual acuity and/or visual field loss (nerve fiber bundle defects) in affected eye(s) • No afferent pupil defect if both eyes affected equally • Fundi are normal or show swollen optic disc(s)


Ancillary Testing • Hemoglobin often very low (from blood loss) • Orbit and brain imaging is usually normal

Differential Diagnosis • Bilateral occipital lobe infarction • Pituitary apoplexy • Optic neuritis

Treatment • Correct systemic hypotension • Correct anemia • Hyperbaric oxygen is ineffective

Prognosis • Recovery of vision may occur within weeks but not later

Fig. 3.12 Hypotensive ischemic optic neuropathy. Anesthesia record in a patient undergoing multilevel lumbar spine fusion. Late in the 9-h procedure (red oval), blood pressure has fallen to levels that do not sustain adequate perfusion of the optic nerves.

A

OD

2 3 4 5 6 7

1

2

7 3 4 56 Infarction

1

2

3

4

5

cm

6

7 OD OS

B

Cross sections

Fig. 3.13 Hypotensive ischemic optic neuropathy. Autopsy specimen in a patient who died of exsanguination. (A) Sagittal section through the right optic nerve shows that its central core has undergone hemorrhagic infarction. (B) The infarction affected nearly the entire intraorbital segment of both optic nerves. (After Johnson MW et al. Ophthalmology 1987; 94:1577–1584, with permission.)

Hypotensive Ischemic Optic Neuropathy

OS

1

39

Toxic Optic Neuropathy Key Facts • Slowly progressive binocular visual loss from optic neuropathy caused by systemic medications or toxins • Ethambutol is the most common medication, methanol the most common toxin • Alcohol may also be an optic nerve toxin but is still listed under nutritional deficiency optic neuropathy (see Nutritional deficiency optic neuropathy) • Withdrawal of toxic agents is the only effective treatment • Visual recovery is more likely if offending agent is removed early

Clinical Findings


• • • • • • • •

Slowly progressive painless binocular visual loss Symmetric visual acuity loss in the two eyes rarely worse than 20/200 Pupil reactions normal Optic discs normal or show temporal pallor Peripapillary nerve fiber layer edema present in methanol toxicity Central or cecocentral scotomas Acquired color vision loss At-risk patients: those taking >15 mg/kg per day of ethambutol or those who have ingested methanol as a substitute for ethanol

Ancillary Testing • Blood chemistries show acidosis in acute methanol toxicity • Methanol toxicity: brain imaging may show high T2 signal in basal ganglia and parieto-occipital white matter


Nutritional deficiency optic neuropathy Hereditary optic neuropathy (dominant or Leber type) Optic neuritis Compressive optic neuropathy Paraneoplastic optic neuropathy Psychogenic visual loss

Treatment • Discontinue ethambutol • Treat methanol acidosis

Prognosis • Visual recovery depends on extent of damage

Fig. 3.14 Ethambutol optic neuropathy. Temporal optic disc pallor is evident in both eyes.

Toxic Optic Neuropathy

A

Fig. 3.15 Reversible toxic optic neuropathy caused by linezolid treatment. (A) Ophthalmic findings 11 months after starting linezolid treatment. Top, visual fields show central scotomas; middle, optic discs appear normal (patient is pseudophakic in the left eye); bottom, visual evoked potentials show no signal. (B) Ophthalmic findings 3 months after discontinuing linezolid treatment. Top, visual fields have returned to normal; middle, optic discs appear normal; bottom, visual evoked potentials are normal. (After McKinley SH et al. J Neuroophthalmol 2005; 25:18, with permission.)

B

41

Nutritional Deficiency Optic Neuropathy Key Facts • Slowly progressive binocular visual loss from optic neuropathy caused by systemic chronic nutritional deficiency, particularly of B vitamins • Chronic alcoholism and severe malnourishment are principal settings • Adequate nutrition and cessation of alcohol intake only effective remedies • Visual recovery unpredictable

Clinical Findings • • • • • • •


Slowly progressive painless binocular visual loss Symmetric visual acuity loss rarely worse than 20/200 Pupil reactions normal Optic discs normal or show temporal pallor Central or cecocentral scotomas Profound acquired color vision loss Peripheral neuropathy common

Ancillary Testing • Delayed latency visual evoked potentials provide objective evidence of optic neuropathy • Nerve conduction velocity testing helps diagnose associated peripheral neuropathy • Blood count to rule out anemia of vitamin B12 deficiency


Toxic optic neuropathy Hereditary optic neuropathy (dominant or Leber type) Optic neuritis Compressive optic neuropathy Paraneoplastic optic neuropathy Psychogenic visual loss

Treatment • Improve diet • Stop alcohol intake • Provide single-dose intramuscular thiamine 100 mg followed by oral thiamine 50 mg/day indefinitely • Provide intramuscular vitamin B12 if appropriate

Prognosis • Visual recovery depends on extent of damage

Fig. 3.16 Nutritional deprivation optic neuropathy. Temporal pallor in both optic discs in a patient with a history of chronic heavy alcohol ingestion.

B

Fig. 3.17 Nutritional deprivation optic neuropathy: two autopsy specimens from patients who had optic neuropathy in the setting of severe chronic alcoholism. (A) Right optic nerve shows that axon columns (arrow heads) on the temporal side of the nerve head (enclosed by arrows) are narrow compared with the normal nasal side. (B) Cross-section of left optic nerve stained for myelin (black) shows lack of stain in the circular region corresponding to the maculopapillar bundle, which contains small fibers vulnerable to nutritional deprivation or toxic insult. (A, After Smiddy WE, Green WR. Graefe’s Arch Clin Exp Ophthalmol 1987; 225:321–324; B, after Cogan DG. Neurology of the Visual System. Springfield: Charles C. Thomas; 1976: 176.)

Nutritional Deficiency Optic Neuropathy

A

43

Dominantly Inherited Optic Neuropathy Key Facts • • • • •

Slowly progressive binocular visual loss during first decade Binocularly symmetric visual acuity loss Dominant inheritance Mapped to chromosome 3q No treatment


Slowly progressive binocular visual loss during first decade Visual loss ranges between 20/20 and 20/200 and is usually symmetric Bilateral central or cecocentral scotomas Wedge-shaped temporal optic disc pallor Some patients have sensorineural hearing loss

Ancillary Testing


• Brain imaging to rule out compressive optic neuropathy unless all findings are classic, including clear family history • Genetic studies valuable for documentation

Differential Diagnosis • Compressive optic neuropathy • Psychogenic visual loss

Treatment • None

Prognosis • Visual loss stabilizes by end of first decade but does not recover

Fig. 3.18 Dominantly-inherited optic neuropathy. Both optic discs show wedgeshaped temporal pallor.

Dominantly Inherited Optic Neuropathy

Fig. 3.19 Centrocecal scotomas (red ovals) are evident on automated (Humphrey) perimetry.

45

Leber Hereditary Optic Neuropathy Key Facts • Subacute visual loss affecting one eye then, after weeks to months, the fellow eye • Males aged <40 years most at risk • Slightly swollen, telangiectatic peripapillary nerve fiber layer in affected eye and sometimes in unaffected fellow eye • Diagnosis based on finding mutation at mitochondrial DNA position 11778, 3460, 14484, or 14459 • Visual loss is generally irreversible • No known treatment

Clinical Findings


• • • • •

Subacute onset of painless visual loss in one eye Same event weeks to months later in fellow eye Visual acuity of 20/100 to finger counting and central or cecocentral scotomas May be no afferent pupil defect even when only one eye has suffered visual loss Telangiectatic swelling of peripapillary nerve fiber layer in affected eye and sometimes in unaffected fellow eye (pre-eruptive stage)

Ancillary Testing • Blood test for mitochondrial DNA at position 11778, 3460, 14484, or 14459 will be positive in nearly all cases


Optic neuritis Compressive optic neuropathy Posterior ischemic optic neuropathy Anterior ischemic optic neuropathy Paraneoplastic optic neuropathy Psychogenic visual loss

Treatment • Patients often placed on mitochondrial cocktail, which includes coenzyme Q10, vitamin E, and B vitamins but no evidence of benefit • Patients often advised to stop smoking to avoid free radical generation • Genetic counseling may involve testing of clinically unaffected family members

Prognosis • Visual loss usually irreversible • Partial recovery may occur with DNA mutations at positions 14484 and 3460

Leber Hereditary Optic Neuropathy

Fig. 3.20 Leber hereditary optic neuropathy. Right optic disc is hyperemic and the peripapillary retinal nerve fiber layer is swollen in acute stage of this condition. The left fundus is in the subacute stage, showing nerve fiber layer thickening and mild temporal optic disc pallor.

47

Compressive Optic Neuropathy and Chiasmopathy Key Facts • Visual loss from compression of optic nerves or chiasm by an intraorbital or intracranial mass • Common causes: • sphenoid meningioma • optic nerve sheath meningioma • craniopharyngioma • pituitary adenoma • optic glioma • teratoma or germinoma • anterior visual pathway aneurysm • Visual loss slowly progressive but may occur suddenly • Treatment is directed at the compressive lesion


Clinical Findings • Visual acuity and/or visual field loss (nerve fiber bundle defects for optic nerve damage, hemianopic defects for chiasmal damage) • Afferent pupil defect is common • Optic discs may appear normal, swollen, or pale

Ancillary Testing • High-resolution MRI with contrast should detect the lesion, with two exceptions: 1. optic nerve sheath meningioma (see Optic nerve sheath meningioma) requires fat-suppressed, thin-section, postcontrast orbital sequences 2. aneurysm (see Anterior visual pathway intracranial aneurysm) requires dedicated vascular imaging

Differential Diagnosis • Optic neuritis • Radiation optic neuropathy

Treatment • Cranial surgery, endovascular procedures, radiation, or medication (depending on the lesion and other clinical characteristics)

Prognosis • Visual recovery depends on: • degree of pre-existing axonal loss • ability to decompress visual pathway • lack of complications

Intraorbital mass Intracanalicular mass Chiasmal region mass Intracranial pre-chiasmal mass

Fig. 3.21 Axial view of the anterior visual pathway and the location of the various masses (tumors) that may affect it.

Compressive Optic Neuropathy and Chiasmopathy 49

Sphenoid Meningioma Key Facts • • • • •

Benign tumor that grows from the meninges covering the sphenoid bone Middle-aged women most at risk Visual loss slowly progressive Brain MRI often diagnostic Treatment options are surgery and radiation

Clinical Findings • Slowly progressive visual loss, usually monocular • May have headache, ophthalmoplegia, ptosis, but visual loss often an isolated manifestation • Reduced visual acuity and/or visual field (hemianopic defects are common) • Afferent pupil defect is common • Optic disc(s) may appear normal, swollen, or pale

Ancillary Testing


• Brain MRI is often diagnostic

Differential Diagnosis • Intraorbital optic nerve sheath meningioma • Other intracranial masses (pituitary adenoma, craniopharyngioma, optic glioma, aneurysm) • Atypical optic neuritis • Infiltrative (neoplastic) optic neuropathy

Treatment • Surgical excision • Radiation

Prognosis • Untreated tumors often grow slowly, although after menopause growth often slows or stops • Visual outcome after surgery: • 30% improve • 30% worsen • 40% remain unchanged • Visual outcome after radiation: • 5% improve • 20% worsen • 75% remain unchanged • Visual loss from radiation toxicity is rare if proper dosimetry is applied

Sphenoid Meningioma

Fig. 3.22 Sphenoid wing meningioma. Postcontrast axial T1 MRI shows mass (arrow) growing from the sphenoid ridge and compressing the intracranial left optic nerve.

A

B

Fig. 3.23 Sphenoid wing meningioma. (A) Postcontrast coronal T1 MRI shows a mass (arrow) involving the left orbitocranial area. (B) Postcontrast axial T1 MRI shows that the mass has invaded the lateral orbit (arrow).

51

Optic Nerve Sheath Meningioma Key Facts • • • • •

Benign tumor that grows from meninges of intraorbital optic nerve Painless progressive monocular visual loss Young adult women most at risk Resistance to retropulsion of ipsilateral eye High-resolution orbital imaging with fat suppression and contrast required to detect the lesion • Biopsy only if clinical and imaging features are atypical • Radiation sometimes improves vision and often prevents worsening of vision • Recommended only if visual preservation in the affected eye would be meaningful.

Clinical Findings


• • • •

Slowly progressive painless monocular visual loss Usually little if any proptosis but may have resistance to retropulsion Visual acuity and nerve fiber bundle visual field loss Optic disc(s) may be normal, swollen with or without dilated shunt vessels, or pale • Afferent pupil defect present

Ancillary Testing • High-resolution, fat-suppressed, contrast T1-weighted MRI shows fusiform or nodular thickening and enhancement of affected intraorbital optic nerve • Intracranial extension on to medial sphenoid ridge is common • Imaging findings often diagnostic but dural inflammation (pachymeningitis) can produce similar findings


Dural inflammation (pachymeningitis) Sino-orbital vasculitis Atypical optic neuritis Infiltrative (neoplastic) optic neuropathy Optic glioma

Treatment • Observation or radiation

Prognosis • Without radiation, progressive visual loss occurs in 75% and remains stable in 25% • Intracranial extension of orbital tumor does not occur unless tumor actually arises on sphenoid bone (sphenoid meningioma) • Visual outcome after radiation: • 10% improve • 70% maintain stable vision • 20% have further visual loss • Visual loss caused by radiation toxicity is rare if proper dosimetry is applied

A

Fig. 3.24 Optic nerve sheath meningioma. (A) Postcontrast coronal T1 MRI shows high signal around the right optic nerve. (B) Postcontrast axial T1 MRI shows that the abnormality affects the orbital and intracanalicular segment of the optic nerve (arrow). These imaging findings can be mimicked by inflammatory diseases such as sarcoidosis.

Optic Nerve Sheath Meningioma

B

53

Craniopharyngioma Key Facts • Benign partially cystic congenital tumor originating in sella turcica from remnants of pharyngeal epithelium • May cause clinical symptoms at any age • Brain MRI is often diagnostic • Treat with cautious resection followed by radiation • Recurrent visual loss from tumor cyst formation is common

Clinical Findings


• Reduced visual acuity and/or visual field (hemianopic defect in at least one eye) • In children, visual loss sometimes accompanied by headache, hypopituitarism (especially growth retardation), papilledema, ventriculomegaly, and increased intracranial pressure • In adults, visual loss is the principal symptom but hypopituitarism may occur • Afferent pupil defect is common • Temporal hemianopic defects are common • Optic discs may appear normal, swollen, small, or pale

Ancillary Testing • Brain imaging may be diagnostic in showing mass with heterogeneous signal high on T1 sequences • Blood tests may show hypopituitarism

Differential Diagnosis • Other mass lesions of sellar region (pituitary adenoma, aneurysm, meningioma, germinoma, dermoid or epidermoid, arachnoid cyst, optic glioma, metastatic cancer, multiple myeloma, chordoma, chondrosarcoma, vascular malformations, histiocytosis, primitive neuroectodermal tumor, lymphoma) • Sphenoid sinusitis or mucocele • Lymphocytic hypophysitis • Pituitary abscess • Multiple sclerosis • Sarcoidosis • Radiation damage

Treatment • Transcranial cautious resection and decompression of cysts • Ventriculoperitoneal shunt for unremitting hydrocephalus • Postoperative high-dose radiation

Prognosis

54

• Natural history is progressive visual loss from further tumor growth • Surgery occasionally improves vision, especially if cysts are decompressed • Main purpose is to provide reduced tumor burden so that radiation may be more effective • Aggressive resections associated with permanent worsening of vision • Radiation doses >5000 cGy are necessary to prevent further tumor growth but place patient at risk for radiation optic neuropathy (see Radiation optic neuropathy) and other intracranial radiation complications • Acute visual loss relapses resulting from cyst expansion can often be surgically decompressed but may require permanent drain or radionuclide ablation

Craniopharyngioma

Fig. 3.25 Craniopharyngioma. Precontrast coronal T1 MRI shows an inhomogeneous high signal from a dumbbellshaped mass (arrow). The high signal is caused by the high protein content within this tumor.

55

Pituitary Adenoma Key Facts • Benign tumor caused by hyperplasia of anterior pituitary cells • Young and middle-aged women most at risk • Visual loss usually slow • Sudden expansion of tumor by hemorrhage (pituitary apoplexy) can produce devastating visual loss and rarely death • Most tumors are endocrinologically silent, so visual loss is only symptom • Brain MRI may be diagnostic • Surgery (usually by trans-sphenoidal route) often provides visual improvement • Visual outcome is worse when preoperative visual loss is marked and tumors are extensive

Clinical Findings


• Chronic or subacute visual loss, usually monocular • Sudden visual loss in pituitary apoplexy • Chronic or new headache in 50% • Endocrine function usually normal (two-thirds) but may be abnormal Prolactin-secreting: • galactorrhea or amenorrhea • decreased libido • impotence Growth hormone-secreting: • acromegaly • gigantism Adrenocorticotropin-secreting: • cushingoid features • diabetes • myopathy Thyrotropin-secreting: • hyperthyroidism • goiter Gonadotropin-secreting: • precocious puberty • decreased libido • Hemianopic defects are common • Afferent pupil defect is common • Optic discs appear normal or pale

Ancillary Testing • Brain imaging often diagnostic • Serum tests may show hypopituitarism in hormonally inactive tumors and selective hyperpituitarism in hormonally active tumors • Serum prolactin >200 ng/mL signals prolactinoma

Differential Diagnosis • Other sellar region masses (craniopharyngioma, aneurysm, meningioma, germinoma, dermoid or epidermoid, optic glioma, metastatic cancer, multiple myeloma, chordoma, vascular malformations, histiocytosis, primitive neuroectodermal tumor) • Sphenoid sinusitis or mucocele • Lymphocytic hypophysitis • Pituitary abscess • Multiple sclerosis • Sarcoidosis • Radiation damage

Treatment • Correct hypopituitarism • For prolactinoma, treat first with low-dose dopamine agonist (bromocriptine, cabergoline) • If unresponsive or patient is intolerant to medication, perform trans-sphenoidal surgery • For non-prolactinomas, perform trans-sphenoidal surgery even if the tumor is large but has not extended far beyond the sella, otherwise perform transcranial surgery • Radiation may be used if tumors cannot be managed surgically, if surgery leaves behind substantial tumor, or if there is late regrowth after surgery

Prognosis

56

• Prolactinomas: dopamine agonist therapy often dramatically shrinks tumor and reverses visual loss • Other pituitary adenomas: trans-sphenoidal surgery by experts is generally safe and produces visual improvement in 50%, stabilization in 40%, and worsening in only 10% • If tumor must be approached transcranially, chance of visual recovery is diminished • Late regrowth of tumor is associated with a poor visual outcome

A

Pituitary Adenoma

Fig. 3.26 Pituitary tumor with extrasellar extension. Postcontrast coronal T1 MRI shows a large high-signal mass that elevates and displaces the optic chiasm (arrow) and extends laterally into both cavernous sinuses (arrowheads).

B

Fig. 3.27 Pituitary tumor with recent hemorrhage (pituitary apoplexy). (A) Precontrast axial CT shows round mass in suprasellar cistern with a central bright (high attenuation) area indicating blood (arrow). (B) Precontrast sagittal T1 MRI shows a high-signal mass indicative of fresh blood in a tumor.

57

Optic Glioma (Pilocytic Astrocytoma of Optic Nerves or Chiasm) Key Facts • Congenital low-grade astrocytoma of optic nerves or chiasm • 30–50% of patients have neurofibromatosis type 1 • Usually discovered during first decade • Vision ranges from normal to severely impaired • MRI may be diagnostic in showing intrinsic mass of anterior visual pathway • Biopsy reserved for cases in which imaging is not diagnostic • Chemotherapy and radiation are treatment options but no controlled study available to show efficacy

Clinical Findings • Stationary or progressive visual loss in one eye or both • Iris hamartomas (Lisch nodules) and/or eyelid plexiform neurofibromas may be present • Visual acuity and/or visual field loss • Afferent pupil defect is common • Pendular (monocular or seesaw) nystagmus sometimes • Optic discs normal, swollen, or pale • Proptosis if large intraorbital component


Ancillary Testing • MRI shows intrinsic mass of optic nerves, optic chiasm, optic tracts, or hypothalamus • Brain MRI may also show hamartomas elsewhere that are typical of neurofibromatosis type 1

Differential Diagnosis • Optic nerve sheath meningioma, orbital neurofibroma or schwannoma • Craniopharyngioma • Optic neuritis

Treatment • Biopsy if imaging is not diagnostic • Ventriculoperitoneal shunt to relieve hydrocephalus • No treatment for patients with glioma confined to optic nerve unless there is disfiguring proptosis and eye is blind, in which case consider surgical excision of tumorous optic nerve with sparing of eye and extraocular muscles • Chemotherapy for patients under age 9 with glioma involving the chiasm and/or hypothalamus and who have severe or worsening visual or hypothalamic dysfunction or signs of tumor growth • Cranial radiation is contraindicated for patients with neurofibromatosis because of risks of occlusive vasculopathy and secondary tumors • There are no controlled trials to affirm that any treatment option improves on the natural history

Prognosis • Visual function often stable in untreated patients • Visual decline may result from tumor growth, tumor production of extracellular matrix, or reactive meningeal hyperplasia • Tumors confined to optic nerve have very low grade histology (grade 1 astrocytoma) and generally show little if any growth • Intracranial extension of a tumor originally confined to the orbit has never been reliably documented • Tumors involving optic chiasm and hypothalamus are of a higher histologic grade (grade 2) than tumors confined to optic nerve and may cause considerable morbidity and even death

A

Optic Glioma

Fig. 3.28 Orbital optic glioma. (A) Postcontrast coronal T1 MRI shows enlarged right optic nerve with enhancing (bright) cuff that represents meningeal reaction to the tumor (arrow). (B) Postcontrast axial T1 MRI shows that the tumor is confined to the orbit (arrow). In a child, these imaging findings are sufficiently diagnostic of pilocytic (grade 1) astrocytoma (optic glioma) that biopsy is unnecessary.

B

Fig. 3.29 Intracranial optic glioma. Postcontrast axial T1 MRI shows thickening and enhancement of the optic chiasm (arrow).

59

Anterior Visual Pathway Intracranial Aneurysm Key Facts • Ballooning of a segment of the intracranial carotid artery because of a congenital media defect (saccular or berry aneurysm) or chronic arteriosclerosis and hypertension (fusiform aneurysm) • Affects carotid–ophthalmic artery junction or supraclinoid carotid artery • Causes visual acuity and/or visual field loss by compression of optic nerve or chiasm • Coiling is as effective and safer than clipping but is an option only if the aneurysm has a relatively narrow neck • Recovery of vision depends on preoperative degree of visual damage

Clinical Findings


• • • • •

Chronic (rarely acute) visual loss, usually monocular May have headache or hypopituitary symptoms Visual acuity and/or visual field loss (nerve fiber bundle or hemianopic defects) Afferent pupil defect Optic disc appears normal or pale

Ancillary Testing • Brain CT or MRI usually shows a mass in anterior middle fossa • CT angiography or magnetic resonance angiography is necessary for more secure diagnosis • Conventional catheter cerebral angiography is necessary for best definition, especially if non-invasive studies are equivocal or intervention is being considered

Differential Diagnosis • Other sellar or presellar middle fossa mass lesions

Treatment • Surgical treatment (clipping, wrapping) is challenging because these aneurysms are often large (supraclinoid) or hard to reach and patients often have arteriosclerosis • Intravascular coiling is usually preferred unless the aneurysm has a very wide neck

Prognosis • Without intervention, saccular (berry) aneurysms rupture at 3%/year if <25 mm diameter and at 8%/year if >25 mm diameter • Intervention rarely produces substantial visual recovery—its purpose is to prevent further visual loss and death from rupture • Morbidity and mortality of intervention depend on size of aneurysm and age and health of patient

A

Fig. 3.30 Supraclinoid carotid artery aneurysm. (A) Right carotid lateral cerebral angiogram shows large aneurysm (arrow) arising above the ophthalmic artery branch; it compressed and damaged the right optic nerve. (B) After coiling, the aneurysm no longer fills with contrast dye (arrow).

Anterior Visual Pathway Intracranial Aneurysm

B

61

Traumatic Optic Neuropathy Key Facts • Most optic nerve trauma occurs indirectly from a forceful blow to the ipsilateral brow a few inches above the orbital rim (the sweet spot) • A blow to the sweet spot is transmitted to the optic canal, where the nerve is bruised • There need be no external evidence of trauma • Optic canal fractures are uncommon and incidental • Visual loss is sudden and non-progressive • Some recovery may spontaneously occur within days to weeks • There is no effective treatment • Evidence that high-dose corticosteroid treatment or surgical decompression of the optic canal improves visual outcome is weak • Direct trauma to optic nerve can also result from a blow or laceration of the orbit or eye • Visual loss is then more likely due to retinopathy or choroidopathy

Clinical Findings


• History of blunt trauma to brow • Acute loss of vision in ipsilateral eye • Visual acuity and/or visual field loss (usually nerve fiber bundle but may be hemianopic if chiasm was bruised) • No evidence of periocular or ocular soft tissue injury • Eye appears structurally normal • Afferent pupil defect • Fundus appears normal acutely Optic disc pallor appears ≥4 weeks after injury

Ancillary Testing • Blows to cranium: brain and orbit imaging may be normal or show optic canal or other sphenoid fractures • Blows or lacerations to eye or orbit: imaging may show soft tissue swelling and hemorrhage

Differential Diagnosis • In the proper setting and with full findings, there is no differential diagnosis • If globe was struck, visual loss may result from traumatic retinopathy or choroidopathy (choroidal rupture)

Treatment • High-dose corticosteroid treatment (30 mg/kg loading dose followed by 5.4 mg/ kg per day for 3 days) has been used based on a small benefit of this treatment to the spinal cord if administered within 8 h in acute spinal cord injury • No controlled clinical trial has been done of this regimen in traumatic optic neuropathy • An uncontrolled clinical trial showed no benefit • Experimental studies of optic nerve crush injury suggest that this treatment may be harmful • If an optic canal fracture is present, it may be tempting to surgically decompress the canal because there are many case reports of postoperative visual improvement, but a single uncontrolled clinical trial showed no benefit of this procedure • There is no effective treatment of direct contusion or avulsion injury of the optic nerve

Prognosis • Some visual recovery may occur within weeks but is not the rule 62

Fig. 3.31 Traumatic optic neuropathy. Precontrast axial CT shows a left optic canal fracture (arrow) in a patient who sustained permanent and complete loss of vision in the left eye after being struck in the head. Caution: optic canal fractures are present in only a minority of patients who suffer traumatic optic neuropathy!

Traumatic Optic Neuropathy

Hemorrhage

Tear

Fig. 3.32 Autopsy specimen of intracanalicular optic nerve in a patient who died after a strong blow to the forehead. The specimen shows a tissue cleft and hemorrhages. The pathology of traumatic optic neuropathy may look like this. (From Lindenberg R et al. Neuropathology of Vision. An Atlas. Philadelphia: Lea & Febiger; 1973: 167, with permission.)

63

Radiation Optic Neuropathy Key Facts • Sudden, often stepwise, and usually irreversible visual loss caused by infarction of intracranial optic nerve(s) or optic chiasm • Occurs months to years after radiation treatment of paranasal sinus or cranial base tumors • Rare event (<2%) except if: • total dose >6000 cGy • daily dose fraction >200 cGy • patient has pre-existing arteriolar sclerosis or diabetes • there has been a breach in delivery technique • Eye and surrounding tissues appear structurally normal • Afferent pupil defect is usually only objective sign • No effective treatment (corticosteroids and hyperbaric oxygen have been tried but without benefit) • Visual loss is irreversible



Acute painless visual loss, usually monocular Visual acuity and/or visual field loss (nerve fiber bundle or hemianopic defects) Eyes and surrounding tissues appear structurally normal Afferent pupil defect

Ancillary Testing • Brain MRI shows enhancement and thickening of intracranial segment of affected optic nerve and sometimes optic chiasm

Differential Diagnosis • Orbital or middle fossa tumor • Orbital or middle fossa inflammation • Optic neuritis

Treatment • No effective treatment (corticosteroids and hyperbaric oxygen have been tried but without benefit)

Prognosis • Minimal if any visual recovery • Further visual loss is common, often in a step-wise (stroke-like) pattern

B

Fig. 3.33 Radiation optic neuropathy. (A) Precontrast coronal T1 MRI of the prechiasmatic optic nerves (upper left) and optic chiasm (upper right) shows thickening on the right side (arrows). (B) Postcontrast coronal T1 MRI shows that these thickened areas enhance. Such findings can also be seen in inflammatory and infiltrative (neoplastic) processes.

Radiation Optic Neuropathy

A

65

Graves Optic Neuropathy Key Facts • Slowly progressive monocular or binocular visual loss caused by compression of optic nerves at orbital apex by swollen extraocular muscles • Associated with reduced eye movements but not necessarily with proptosis or marked conjunctival or eyelid swelling • Orbit CT or MRI shows swollen extraocular muscles at orbital apex • Surgical orbital (especially medial) wall decompression is definitive treatment • Systemic and intraorbital corticosteroid treatment may provide short-term benefit • Orbital radiation may provide long-term benefit

Clinical Findings


• History of thyroid dysfunction (hyperthyroidism or hypothyroidism) and its treatment • Slowly progressive visual acuity and/or visual field loss (usually binocular) • Lid retraction and lag • Conjunctival and eyelid congestion but need not be severe • Resistance to retropulsion of globes • Reduced ocular ductions often in all directions • Subnormal visual acuity and/or nerve fiber bundle visual field defects • Optic discs appear normal, swollen, or pale

Ancillary Testing • Thyroid function may be normal, subnormal, or supernormal • Orbit CT or MRI shows swollen extraocular muscles and absence of space between them and the optic nerve at the orbital apex

Differential Diagnosis • Atypical optic neuritis • Infiltrative (neoplastic) optic neuropathy • Orbital tumor

Treatment • Surgical orbital (especially medial) wall decompression must extend to orbital apex • Systemic and intraorbital corticosteroid treatment may provide short-term benefit by reducing orbital soft tissue edema • Orbital radiation may provide benefit by reducing apical orbital congestion if surgery has been ineffective

Prognosis • Visual recovery depends on degree of pre-existing visual dysfunction • Surgical orbital decompression is generally safe and may provide stabilization or improvement in visual function • Radiation may also be effective • Corticosteroid treatment usually provides rapid but only temporary improvement in vision

66

Fig. 3.34 Graves optic neuropathy. The lids are swollen and the conjunctiva is hyperemic.

Graves Optic Neuropathy

A

B

Fig. 3.35 Graves optic neuropathy. Orbital CT of the patient shown in Fig. 3.34. (A) Axial and (B) coronal images show enlarged extraocular muscles. In the posterior orbit, they compress and damage the optic nerve.

67

Papilledema Key Facts • Acquired swelling of optic discs caused by increased intracranial pressure (ICP) • May be difficult to distinguish from congenital optic disc elevation (pseudopapilledema) or other causes of acquired optic disc edema • Optic disc swelling nearly always bilateral but can be asymmetric • Relative preservation of visual function in early stages distinguishes papilledema from other causes of acquired optic disc edema • Continued ICP elevation may eventually kill optic nerve axons and cause severe and irreversible visual loss (atrophic papilledema) • Treatment is aimed at reducing ICP (eliminating the cause, acetazolamide, cerebrospinal fluid diversion procedures) and protecting the optic nerve (optic nerve sheath fenestration)

Clinical Findings


• Episodic dimming or complete blackout of vision lasting seconds in one or both eyes, occurring spontaneously or on standing (transient obscurations of vision) • Head, neck, or interscapular pain • Pulsatile tinnitus • Visual acuity usually normal • Visual fields show inferonasal nerve fiber bundle defects • Optic disc margin elevation and blurring usually binocular but may be asymmetric • Mild papilledema: elevation of neuroretinal rim tissue and obscuration of optic disc margin and adjacent peripapillary retina by swollen axons with preservation of physiologic cup • Marked papilledema: loss of physiologic cup with papillary and peripapillary hemorrhages, cotton wool spots, and (rarely) hard exudates • Chronic papilledema: glazed disc surface with telangiectasia • Atrophic papilledema: axon death causes a gray-white disc that has flattened out

Ancillary Testing • Brain MRI may: • be normal • show non-specific signs of high ICP (flattening of posterior sclera, expansion of perioptic spaces, empty sella turcica, and descent of cerebellar tonsils) • show a mass, dilated ventricles, or dural sinus thrombosis • If brain imaging is normal, lumbar puncture is performed


Congenitally anomalous elevated optic discs (pseudopapilledema) Atypical optic neuritis Ischemic optic neuropathy Hypertensive optic neuropathy Diabetic papillopathy Leber hereditary optic neuropathy Central retinal vein occlusions Infiltrative (neoplastic) optic neuropathy

A

Papilledema

B

C

Fig. 3.36 Different degrees of papilledema. (A) Mild papilledema. (B) Marked papilledema. (C) Chronic papilledema.

69

Papilledema (Continued) Treatment • Direct treatment at underlying cause if possible • Reduce ICP with medication (acetazolamide, topiramate, furosemide) • Mass effect from brain tumor: treat with dexamethasone, radiation, or intracranial surgery • Dural sinus thrombosis: consider using heparin • Obstructive hydrocephalus: perform internal or external shunt procedure • Idiopathic intracranial hypertension: treat as recommended under Idiopathic intracranial hypertension (pseudotumor cerebri )

Prognosis


• Depends on underlying cause • Severe and/or chronic papilledema can cause death of optic disc axons, perhaps by ischemia • No reliable indicators of which patients are at greatest risk of vision loss • Residual vision can be preserved and even improved if ICP is promptly relieved or optic nerve sheath is promptly fenestrated

A

C

Papilledema (continued)

B

Fig. 3.37 Postpapilledema optic neuropathy. (A) Preoperatively, low-grade glioma displaces the brain (left) and causes papilledema. (Patient was too ill to undergo visual field examination.) (B) Six weeks postoperatively, the tumor has been fully resected and papilledema has evolved into optic disc pallor, greater in the left eye. (C) Six weeks postoperatively, visual fields show substantial nerve fiber bundle loss, greater in the left eye.

71

Idiopathic Intracranial Hypertension (Pseudotumor Cerebri) Key Facts • Increased intracranial pressure (ICP) without ventriculomegaly or other structural brain abnormalities • Caused by impaired drainage of cerebrospinal fluid (CSF) at arachnoid granulations • Major concern is damage to optic nerves • Overweight young women most at risk • Visual dysfunction may be mild or severe

Clinical Findings


• Episodic dimming or complete blackout of vision lasting seconds in one or both eyes, occurring spontaneously or on standing (transient obscurations of vision) sometimes • Head, neck, or interscapular pain sometimes • Pulsatile tinnitus sometimes • Visual acuity usually normal • Visual fields normal or show nerve fiber bundle defects • Esotropia sometimes • Optic disc edema (papilledema), usually bilateral but may be asymmetric • Neurologic examination normal except for findings attributable to high ICP

Ancillary Testing • Brain MRI and magnetic resonance venography normal • Lumbar puncture has opening pressure >20 cm H20 and normal cerebrospinal constituents • Beware of falsely elevated CSF opening pressure from poor lumbar puncture technique, unrelaxed patient, or ketamine sedation


Congenitally anomalous elevated optic discs (pseudopapilledema) Atypical optic neuritis Ischemic optic neuropathy Hypertensive optic neuropathy Diabetic papillopathy Leber hereditary optic neuropathy Central retinal vein occlusions Infiltrative (neoplastic) optic neuropathy

Treatment • Papilledema mild and stable and visual function normal: observe without treatment • Papilledema severe or visual function threatened: lower ICP with acetazolamide (or less potent alternatives furosemide or topiramate) • Visual function already severely compromised or rapidly worsening, or patient is non-compliant or unresponsive to medication: perform ventriculoperitoneal shunt procedure • Lumboperitoneal shunting is no longer favored because of complications • Management options include: • observation • weight loss • oral agents that lower CSF production • ventriculoperitoneal shunt • optic nerve sheath fenestration • Permanent optic neuropathy may result if treatment is inadequate or occurs late • Optic nerve sheath fenestration is alternative to shunting but does not reliably lower ICP • Weight loss programs are advisable but rarely effective • Consider gastroplasty for intractable morbid obesity

A

Fig. 3.38 Papilledema (A) before and (B) after 3 weeks of treatment with acetazolamide. Papilledema improved substantially on medical treatment and vision returned to normal. No surgery was needed.

Idiopathic Intracranial Hypertension

B

73

Idiopathic Intracranial Hypertension (Continued) Prognosis • No reliable indicators of which patients are at greatest risk of vision loss from papilledema • Medical treatment usually reverses papilledema and protects vision • Condition eventually remits spontaneously • Ventriculoperitoneal shunting reliably lowers ICP and carries no risk to vision but may cause: • meningitis • shunt blockage • CSF over-drainage • intractable postural headache from intracranial hypotension • Optic nerve sheath fenestration may protect optic disc by causing a scar at the surgical site • It does not lower ICP, it requires procedures on both optic nerves, and there is a risk of infarcting optic nerve or retina • Residual vision can be preserved and even improved if shunt or nerve sheath fenestration is performed promptly


A

Fig. 3.39 Papilledema (A) before and (B) after treatment with ventriculoperitoneal shunting. The pretreatment papilledema shows acute features (hemorrhage) and chronic features (pallor). Visual function was severely impaired at outset. Visual function improved with shunting, but posttreatment optic disc pallor is evident. Visual fields did not return to normal.

Idiopathic Intracranial Hypertension (continued)

B

75

Hypertensive Optic Neuropathy Key Facts • Optic disc edema caused by rapid rise in systemic blood pressure • Represents vasogenic edema from optic disc vessel incompetence • Always associated with hypertensive retinopathy (cotton wool spots; flame, dot, blot, and boat hemorrhages) and sometimes choroidopathy (serous retinal detachments) • Visual loss not usually caused by optic neuropathy but by serous maculopathy and/or reversible posterior leukoencephalopathy syndrome • Treat by lowering blood pressure about 10 mmHg/h • More rapid lowering rate risks hypotensive optic neuropathy • Visual loss reversible if treatment started early

Clinical Findings


• Optic disc edema with or without papillary hemorrhages • Cotton wool spots; flame, dot, blot, or boat hemorrhages (hypertensive retinopathy), and sometimes serous retinal detachments (hypertensive choroidopathy) • Visual acuity and visual field loss usually mild unless there is serous maculopathy or posterior leukoencephalopathy

Ancillary Testing • Systemic blood pressure relatively high • Renal failure may be present • Brain MRI may show cerebral hemispheric white matter high signal on FLAIR and T2 but normal diffusion-weighted imaging (reversible posterior leukoencephalopathy syndrome)


Atypical optic neuritis Ischemic optic neuropathy Papilledema Diabetic papillopathy Leber hereditary optic neuropathy Retinal vasculitis Central retinal vein occlusions Reversible posterior leukoencephalopathy syndrome

Treatment • Lower blood pressure about 10 mmHg/h • More rapid lowering rate risks hypotensive optic neuropathy • Treat underlying cause of hypertension if possible

Prognosis • Recovery of vision usually complete if hypertension promptly (but not too rapidly) corrected • Prolonged untreated malignant hypertension can lead to infarction of optic disc and other parts of brain

76

Hypertensive Optic Neuropathy

Fig. 3.40 Hypertensive optic neuropathy and retinopathy. Bilateral optic disc edema with extensive peripapillary and retinal cotton wool spots. Optic nerve dysfunction is mild in this condition. Visual loss is more often due to retinal edema or microinfarction or posterior reversible encephalopathy syndrome (see Fig. 4.5).

77

Infiltrative (Neoplastic) Optic Neuropathy Key Facts


• Visual loss caused by infiltration of the optic nerves or chiasm by metastatic solid or hematopoietic cancer • Implies meningeal spread of cancer • Most common cancers: • lung • breast • lymphoma • leukemia (may be occult) • Visual loss may be an isolated clinical manifestation • Brain and orbit MRI normal or shows enhancing optic nerve(s), chiasm, or meninges • Diagnosis confirmed by examination of spinal fluid, including spin-down cytology and flow cytometry • Visual recovery possible with parenteral corticosteroids, whole brain radiation, and antineoplastic therapy (often delivered intrathecally) • Death usually follows within 2 years


Subacute monocular or binocular visual loss Visual acuity or visual field loss in one or both eyes Optic discs usually normal but may be swollen May be first sign of cancer or only sign of relapse

Ancillary Testing • Other sites of cancer are usually discoverable with advanced imaging modalities (including PET) but sometimes an exhaustive search is negative • Brain and orbit MRI may be normal, show enhancing optic nerves or chiasm, or meninges, or, less commonly, brain metastatic masses • Diagnosis confirmed on lumbar puncture but may require multiple lumbar punctures with spin-down cytology and flow cytometry


Optic neuritis Ischemic optic neuropathy Compression of optic nerves or chiasm by orbital or intracranial masses Radiation optic neuropathy Paraneoplastic optic neuropathy

Treatment • Intravenous high-dose corticosteroids (1 g/day for 3–5 days) • Whole brain radiation • Intravenous, oral, or intrathecal chemotherapy

Prognosis • Recovery of vision is variable • Despite treatment, death from widespread cancer usually occurs within 2 years

78

A

B

Fig. 3.41 Infiltrative (neoplastic) optic neuropathy in the setting of widespread carcinomatous meningitis from adenocarcinoma of the lung. The patient reported left eye visual loss and numbness on both sides of the face and in the perineum. (A) Postcontrast coronal T1 MRI shows enhancement of the left optic nerve (arrow). (B) Postcontrast axial T1 MRI shows enhancing masses in Meckel’s cave bilaterally (arrows). (C) Postcontrast axial spine MRI shows matting of the roots in the cauda equina (arrows). In this projection, they normally appear as thin white dots, not large clumps.

Fig. 3.42 Lymphomatous meningitis. Axial FLAIR MRI shows excessively bright signal in the sulci (arrows), a sign of increased protein in the cerebrospinal fluid, caused here by lymphomatous meningitis that also damaged the optic nerves.

Infiltrative (Neoplastic) Optic Neuropathy

C

79

Paraneoplastic Optic Neuropathy Key Facts • Subacute visual loss in one eye or both in a patient with lung cancer • Caused by autoimmune destruction of optic nerve(s) as the result of crossreaction to tumor antigens (molecular mimicry) • Much less common than infiltrative optic neuropathy and less common than paraneoplastic retinopathy • History of lung cancer typical but evidence of metastasis is uncommon • May also have other paraneoplastic neurologic manifestations (ataxia and encephalopathy) • Optic discs appear normal or swollen • Diagnosis confirmed by finding paraneoplastic antibody (CRMP-5) or other antibodies in blood, but paraneoplastic antibody screen often negative • Treatment of underlying cancer may produce visual improvement

Clinical Findings


• Subacute monocular or binocular visual loss • Optic discs appear normal or swollen • May also have ataxia and mental status changes

Ancillary Testing • Body imaging may show signs of lung cancer • Brain imaging usually normal • Paraneoplastic antibody screen usually negative, but CRMP-5 antibody may be found

Differential Diagnosis • Infiltrative (neoplastic) optic neuropathy • Optic neuritis • Ischemic optic neuropathy

Treatment • High-dose corticosteroid, plasmapheresis, or intravenous immunoglobulin • Treatment of underlying cancer

Prognosis • Treatment may sometimes produce visual improvement, which may also occur spontaneously • Treatment of underlying cancer may improve visual outcome

Paraneoplastic Optic Neuropathy

Fig. 3.43 Paraneoplastic optic neuropathy autopsy findings. Microscopic section of the optic nerve shows prominent spongiosis (S) and perivascular lymphocytic infiltrate (arrow) (hematoxylin and eosin). (After Sheorajpanday R et al. J Neuroophthalmol 2006; 26:168–172, with permission.)

81

Diabetic Papillopathy Key Facts • Nerve fiber bundle visual loss associated with chronic optic disc swelling in patients with insulin-dependent or non–insulin-dependent diabetes mellitus • May be indolent form of anterior ischemic optic neuropathy • Visual loss monocular or binocular, subacute or chronic, and usually mild • Optic discs have distinctive appearance of diffuse swelling with surface telangiectasia • Often confused with papilledema or diabetic optic disc neovascularization • Diabetic retinopathy need not be present • Optic disc findings usually resolve spontaneously within a year • Visual loss may not recover fully • There is no treatment

Clinical Findings


• • • •

Subacute or chronic visual loss, monocular or binocular Visual acuity and/or visual field loss (nerve fiber bundle defects) typically mild Diffuse optic disc edema with surface telangiectasia in one or both eyes Diabetic retinopathy either absent or mild

Ancillary Testing • Fluorescein angiography shows leakage within disc substance (not into vitreous, as seen in diabetic neovascularization) • Brain and orbit imaging is negative • Lumbar puncture, indicated in bilateral cases, shows normal opening pressure and cerebrospinal fluid constituents


Papilledema Congenitally elevated optic disc(s) Ischemic optic neuropathy Proliferative diabetic retinopathy Optic neuritis Hypertensive optic neuropathy Infiltrative optic neuropathy

Treatment • Good control of blood sugar is recommended but no evidence of efficacy

Prognosis • Visual loss may resolve spontaneously • Optic disc abnormalities eventually resolve to normal or pallor after many months • Neovascularization of optic disc may occur soon afterward

82

Diabetic Papillopathy

Fig. 3.44 Diabetic papillopathy. The elevated hyperemic disc with tufts of small blood vessels on its surface is typical of this condition.

83

Section 4 Retrochiasmal Vision Disorders Homonymous Hemianopia

86

Cerebral (Retrogeniculate, Cortical) Blindness

88

Visual Agnosia

92

Visual Spatial And Attentional Disturbances

94

Homonymous Hemianopia Key Facts • Temporal field defect in one eye and nasal field defect in the other eye, with defect borders aligned to vertical meridian • Lesion usually lies in visual cortex but could be in optic tract or optic radiations • Common causes: • infarction • closed head injury • lobar hemorrhage • tumor • reversible posterior leukoencephalopathy syndrome (RPLS) • If defects are large, patients are not permitted to drive a passenger car in most locales • No solid evidence that visual training or optical devices afford benefit

Clinical Findings

SECTION 4 • Retrochiasmal Vision Disorders

• Vision loss in one or both hemifields, difficulty reading, sometimes with visual hallucinations and perceptual distortions • Visual field defects may be • unilateral or bilateral • complete or incomplete • quadrantic • paracentral • sparing the central 10º (macular sparing) • crescentic (limited to unpaired temporal crescent beyond 30º of fixation) • sparing the temporal crescent (temporal crescent sparing) • Visual acuity is spared unless defects are bilateral and involve the paracentral region on both sides • Pupil reactions and optic discs are normal

Ancillary Testing • Acute infarcts: CT may be normal within first 48 h, but MRI diffusion-weighted studies are always abnormal from the outset, showing areas of restricted diffusion in occipital lobe (cytotoxic edema) • Tumors or hemorrhages: CT and MRI always show abnormalities from outset • RPLS: MRI shows high signal on FLAIR and T2 MRI in posterior cerebral white matter but no restricted diffusion (vasogenic edema)

Differential Diagnosis • Common causes: • ischemic stroke • occipital hemorrhage • RPLS • occipital tumor • Uncommon causes: • adrenoleukodystrophy • mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) • acute disseminated encephalomyelitis • multiple sclerosis • toxic leukoencephalopathy (methanol, cyclosporine, intrathecal methotrexate, brain irradiation) • progressive multifocal leukoencephalopathy • Alzheimer disease • Creutzfeldt–Jakob disease • sagittal sinus thrombosis • hypoxic encephalopathy • head trauma • Do not forget psychogenic visual loss

Treatment • No solid evidence that visual training or optical devices afford benefit

Prognosis • Patients compensate with adaptive eye movements, but if defects are large they are not permitted to drive a passenger car in most locales 86

Homonymous Hemianopia

Fig. 4.1 Automated (Humphrey perimeter) visual fields show a dense right homonymous hemianopia.

Fig. 4.2 Homonymous hemianopia caused by left optic radiations and visual cortex infarction. Axial FLAIR MRI shows a left occipital lobe signal abnormality in the distribution of the left posterior cerebral artery (arrow), consistent with infarction.

87

Cerebral (Retrogeniculate, Cortical) Blindness Key Facts


• Severe, often total, visual loss in both eyes from lesions affecting optic radiations or visual cortex in both cerebral hemispheres • Common causes in adults: • bilateral infarctions of occipital lobe cortex and/or posterior optic radiations • reversible posterior leukoencephalopathy syndrome (RPLS) • trauma • Common causes in children: • periventricular leukomalacia • cerebral maldevelopment • trauma • Reversible causes: • RPLS • focal status epilepticus • metabolic encephalopathy (hypoglycemia, hepatic encephalopathy, post dialysis) • acute disseminated encephalomyelitis or multiple sclerosis • occipital tumor • brain abscess • meningitis • MRI reliably detects lesion except in: • metabolic encephalopathy • Creutzfeldt–Jakob disease (CJD) • meningoencephalitis • focal status epilepticus • If MRI is negative and patient is otherwise neurologically intact, the diagnosis is likely to be psychogenic blindness

Clinical Findings • Binocular symmetric visual loss with normal-appearing eyes and normal pupillary reactions to light • Visual loss usually severe, often total • Visual hallucinations often present • Patients may insist (confabulate) that they can see (Anton syndrome) • No other neurologic abnormalities need be present • Bilateral homonymous hemianopias sometimes evident on visual field testing

Ancillary Testing • Brain MRI shows pertinent abnormalities except in metabolic encephalopathy, CJD, and focal status epilepticus • Electroencephalogram should be performed if focal status epilepticus is a consideration • Rule out hypoglycemia and hepatic encephalopathy, especially if MRI is negative • Lumbar puncture to rule out infection if no other explanation exists

88

A

B

C

Cerebral (Retrogeniculate, Cortical) Blindness

Fig. 4.3 Consecutive bilateral posterior cerebral infarctions. (A) Axial FLAIR MRI shows high signal in the distribution of the right calcarine artery (arrow) and very low signal in the distribution of the left parieto-occipital artery. (B) Diffusionweighted MRI shows high signal in the right occipital region. (C) Apparent diffusion MRI shows a low signal in that region, confirming that the right occipital infarction is recent. The left parieto-occipital infarction is old and has caused destruction of tissue (encephalomalacia).

Fig. 4.4 Progressive multifocal leukoencephalopathy causing cerebral blindness. Axial FLAIR MRI shows ex vacuo dilatation of occipital horns and high signal in the remaining occipital white matter.

89

Cerebral (Retrogeniculate, Cortical) Blindness (Continued) Differential Diagnosis

SECTION 4 • Retrochiasmal Vision Disorders 90

• • • • • • • • • • • • • • • • • • • • • •

Bilateral infarctions of occipital lobe cortex and/or posterior optic radiations RPLS Closed head injury Focal status epilepticus Metabolic encephalopathy (hypoglycemia, hepatic encephalopathy, post dialysis) Acute disseminated encephalomyelitis or multiple sclerosis Progressive multifocal leukoencephalopathy Occipital tumor or its treatment Occipital hemorrhage Trauma Abscess Meningoencephalitis Radiation and intrathecal methotrexate leukoencephalopathy Sagittal venous sinus thrombosis Alzheimer disease CJD X-linked adrenoleukodystrophy Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) Periventricular leukomalacia Cerebral maldevelopment Delayed visual cortical maturation Psychogenic

Treatment • Depends on underlying lesion

Prognosis • Depends on underlying lesion

A

B

C

Fig. 4.6 Hypoxic–ischemic encephalopathy in a 10 monthold victim of strangulation. Axial CT performed 1 month after the event shows signs of infarction, especially in occipital lobes. Dark areas (arrowheads) represent ischemic edema and bright strips (arrows) represent laminar dystrophic calcification.

Cerebral (Retrogeniculate, Cortical) Blindness (continued)

Fig. 4.5 Reversible posterior leukoencephalopathy syndrome in a patient with hypertension of pregnancy and subacute bilateral blindness. (A) Axial FLAIR MRI performed at time of blindness shows high signal in the occipital and temporal lobes. (B) Diffusion-weighted MRI shows no restricted diffusion, indicating that the high FLAIR signal represents vasogenic edema rather than cytotoxic edema of recent stroke. (C) Axial FLAIR MRI performed 2 weeks after induced delivery of the baby, correction of hypertension, and gradual full recovery of vision. It shows no abnormalities.

91

Visual Agnosia Key Facts • Visual recognition disturbance attributed to dysfunction of temporal cortex or its connections to visual cortex • Lack of ability to identify familiar faces, objects, colors, or symbols by sight • Tactile and auditory recognition are intact • Basic vision, language, and other cognitive functions are intact • Considered a failure to link visual images to stored information in language or memory cortex • Common causes: • stroke • progressive multifocal leukoencephalopathy • tumor • radiation • Alzheimer disease


Clinical Findings • Object agnosia: inability to describe the use of familiar objects (glasses, pen, coins) when they are displayed visually • deficit disappears when objects are handled • Face agnosia (prosopagnosia): inability to identify familiar or family faces • Place agnosia (topographic agnosia): inability to recognize familiar places • Cerebral achromatopsia: inability to name and match colors • Pure alexia: inability to read yet ability to spell and write to dictation • May be accompanied by superior homonymous hemianopias (object, face, place agnosia) or right homonymous hemianopia (pure alexia)

Ancillary Testing • Brain MRI discloses a bilateral occipitotemporal lesion in most cases of object agnosia, prosopagnosia, and cerebral achromatopsia, and a left occipitotemporal lesion in pure alexia • in Alzheimer disease, there is only diffuse cerebral atrophy • Detailed neuropsychometric testing is helpful to better characterize the deficits

Differential Diagnosis • Psychogenically based lack of cooperation • Global cognitive disturbance • Aphasia



92

Fig. 4.8 Pure alexia in left occipital infarction. Diffusionweighted MRI shows high signal from the mesial temporal to the occipital lobe (arrow), a sign of infarction in the distribution of the left posterior cerebral artery. The patient had a right homonymous hemianopia and pure alexia.

Visual Agnosia

Fig. 4.7 Visual recognition disturbances caused by bilateral temporal and occipital infarction. Axial FLAIR MRI performed 1 year after the event shows high signal in the inferior temporal and occipital regions more on the right (arrow) than left side. The patient initially had an inability to identify colors (acquired achromatopsia), familiar faces (proposagnosia), familiar places (topographic agnosia), and some familiar objects (visual object agnosia).

93

Visual Spatial and Attentional Disturbances Key Facts


• Visual spatial and visual attention disturbances attributed to dysfunction of inferior parietal cortex or its connections to visual cortex • Lack of ability to: • detect all objects in a visual array • localize objects in space • interpret action in photographs • walk confidently • Visual acuity and visual field loss do not explain these deficits • Sometimes lack of ability to generate voluntary eye movements (acquired ocular motor apraxia) • Visual and eye movement components may be present (Balint syndrome; see Acquired ocular motor apraxia [supranuclear gaze palsy]) • Considered a failure to link visual images to parietal centers governing spatial concepts and distribution of attention, and impairment of parietal centers that mediate voluntary gaze • Common causes: • watershed stroke • Alzheimer disease • progressive multifocal leukoencephalopathy • tumor • radiation • sagittal sinus thrombosis

Clinical Findings • Inability to point accurately to objects in space (optic ataxia) • Inability to accurately count arrays of objects or to identify actions in pictures (simultanagnosia) • Inability to detect stimuli in peripheral visual field, especially when fixing on a central target or being shown more than one stimulus at a time • Field widens when patient views a blank surface or is shown only one stimulus at a time (visual inattention) • Inability to generate voluntary eye movements but ability to generate reflex eye movements • Basic vision, language, and other cognitive functions are intact • May be accompanied by inferior bilateral homonymous hemianopia

Ancillary Testing • Brain imaging virtually always discloses a bilateral occipitoparietal lesion • The exception is Alzheimer disease, in which there may be diffuse cerebral atrophy • Detailed neuropsychometric testing is helpful to better characterize the deficits

Differential Diagnosis • Psychogenically based lack of cooperation • Global cognitive disturbance



94

A

B

Fig. 4.9 When shown this picture of a baseball (A), a patient with a visual spatial and attentional disturbance might indentify it as railroad tracks (B), that is, the patient notices the seams of the ball but does not integrate them with the circle to identify the object correctly.

B

C

Fig. 4.10 Visual spatial and attention disturbances caused by bilateral parietooccipital infarcts attributed to primary central nervous vasculitis. (A) Axial FLAIR MRI shows high signal in parieto-occipital regions (arrows). (B) Diffusion-weighted MRI shows high signal in the same areas. (C) Apparent diffusion MRI shows low signal in the same areas, confirming that these findings indicate restricted diffusion from cytotoxic edema of recent infarction.

Visual Spatial and Attentional Disturbances

A

95

Section 5 Extraocular Muscle Disorders Orbital Myositis

98

Graves Disease

100

Genetic Extraocular Myopathy

102

Myasthenia Gravis

104

Orbital Myositis Key Facts • Subacute, usually monocular, non-infectious inflammation of one or more of the extraocular muscles • Usually orbital congestion • Diplopia • May be associated with systemic connective tissue or vasculitic disorder • Orbital imaging (CT or MRI) usually shows enlargement and enhancement of affected extraocular muscles • Biopsy not necessary at outset unless orbital imaging is not diagnostic

Clinical Findings

SECTION 5 • Extraocular Muscle Disorders

• Ductional deficits in affected eye • Diplopia • Tenderness to palpation, eyelid edema, conjunctival congestion, proptosis, increased resistance to retropulsion of eye • Incomitant ocular misalignment • Forced ductions may show impaired eye movement • In very indolent cases, increased resistance to retropulsion of the globe may be the only clue to diagnosis

Ancillary Testing • Orbital imaging (CT or MRI) usually shows enlargement and enhancement of affected extraocular muscles and their tendons and higher signal within intraconal fat (fat stranding) • Laboratory studies related to systemic autoimmune condition are indicated if the ophthalmic manifestations linger or there are suggestive systemic symptoms • Orbital biopsy necessary only if clinical and imaging features are not diagnostic or the ophthalmic manifestations remain active despite medical treatment


Graves disease Primary or metastatic orbital tumor Orbital cellulitis Sino-orbital aspergillosis or mucormycosis Carotid–cavernous fistula

Treatment • Prednisone 0.5–1 mg/kg per day • If this medical regimen is not effective or imaging is not diagnostic, consider biopsy • Corticosteroid-sparing agent may be necessary if long-term treatment required • Orbital radiation reserved for refractory cases • Spectacle prisms may provide relief from diplopia in active and chronic phases • Eye muscle surgery indicated for bothersome diplopia once disease no longer active and misalignment is stable for at least 6 months

Prognosis • • • • 98

Usually very responsive to prednisone but often recurs if prednisone tapered Usually becomes inactive after months but often recurs Systemic autoimmune condition may appear later In diplopia refractory to prism or eye muscle surgery, spectacle or contact lens occluder useful to relieve diplopia • Eye muscle surgery may restore a useful zone of single binocular vision

Orbital Myositis

Fig. 5.1 Right orbital myositis. Abduction and supraduction are reduced in the right eye. Caution: orbital myositis may produce any ductional deficit. It more commonly affects one eye but may involve both; it differs from Graves disease (see Fig. 5.2) in being of more rapid onset and producing periocular pain on the involved side.

99

Graves Disease Key Facts • Subacute or chronic but self-limited inflammation of extraocular muscles and other orbital soft tissues associated with autoimmune reaction to thyroid gland • Usually binocular but may be markedly asymmetric • Periocular discomfort but no pain • Lid edema, lid retraction, and lid lag in most patients • Conjunctival edema (chemosis), tearing, proptosis, and hyperemia over insertion of extraocular muscles • Reduced ocular ductions, especially in upgaze, causing diplopia • Imaging often shows swelling of extraocular muscles with sparing of tendons • In active phase, treatment usually palliative but some clinicians use short-term oral corticosteroids • Orbital wall removal recommended only for optic neuropathy

Clinical Findings


• Hyperthyroidism or hypothyroidism and goitrous neck mass may be present, but patients may also be euthyroid • Lid retraction and lag, eyelid edema, conjunctival congestion, proptosis • Limited ocular ductions owing to swelling or scarring of extraocular muscles

Ancillary Testing • Thyroid function tests may show hyperthyroidism, hypothyroidism, or euthyroidism • Orbital imaging (CT or MRI) usually shows enlargement and enhancement of affected extraocular muscles with sparing of their tendons • Forced ductions (passive ductions) testing may be positive but is not necessary for diagnosis—should be avoided because often causes pain and unsightly subconjunctival hemorrhage


Orbital myositis Primary or metastatic orbital tumor Orbital cellulitis Sino-orbital aspergillosis or mucormycosis Carotid–cavernous fistula

Treatment • In active phase, raise head of bed, use systemic diuretics and/or vasoconstrictor eyedrops • Short-term oral corticosteroids may provide palliative relief of periocular discomfort and diplopia, but long-term use is associated with dangerous side effects • Surgical orbital wall decompression recommended for optic neuropathy if imaging shows clear evidence of compression (see Graves optic neuropathy) • Spectacle prisms or monocular occlusion may eliminate bothersome diplopia • Once disease becomes inactive, extraocular muscle surgery, spectacle prisms, or monocular occlusion may eliminate bothersome diplopia

Prognosis

100

• Eyelid, extraocular muscle, and conjunctival inflammation eventually burn out after several years but often leave eyelid retraction, proptosis, and scarred muscles, causing ocular misalignment and diplopia • Prisms and/or extraocular muscle surgery are often successful in palliating diplopia

Graves Disease

Fig. 5.2 Graves disease. Left hypertropia in primary gaze position. Supraduction is reduced in both eyes, more in the right eye. Any ocular motility disturbance may be seen in Graves disease, but reduced supraduction is most common as the result of restriction of ocular movement by a scarred and shortened inferior rectus muscle.

101

Genetic Extraocular Myopathy Key Facts • Ocular ductional deficits caused by mitochondrial or nuclear DNA abnormalities • Very slowly progressive or stationary • Common causes: • chronic progressive external ophthalmoplegia • Kearns–Sayre syndrome (KSS) • oculopharyngeal dystrophy (OPD) • myotonic dystrophy (MD) • Ductional deficits may be mild or severe but always symmetric • Diplopia need not be present because ductional deficits are often symmetric • Ptosis is common • Diagnosis based on clinical features and muscle biopsy • Morbidity related to non-ophthalmic features, particularly cardiac conduction defects, which may be life-threatening


Clinical Findings • Symmetric ductional deficits and often ptosis in both eyes • Findings very slowly progressive or stationary • Passive head movement does not improve ductions (negative doll’s head maneuver) • Evidence of pigmentary retinopathy in KSS and MD


Electroretinography for pigmentary retinopathy in suspected KSS and MD Electrocardiography for cardiac conduction defects in suspected KSS and MD Swallowing study in suspected OPD Muscle biopsy for DNA analysis

Differential Diagnosis • Progressive supranuclear palsy • Myasthenia gravis • Chronic inflammatory demyelinating polyradiculoneuropathy

Treatment • These conditions are untreatable—treatment is directed at their manifestations


102

Fig. 5.4 Retinal pigment epithelium degeneration in Kearns-Sayre syndrome. Fundi show peripapillary and posterior pole atrophy in both eyes. Visual acuity was subnormal.

Genetic Extraocular Myopathy

Fig. 5.3 Genetic extraocular myopathy. Ductions are reduced in all directions. Genetic extraocular myopathies generally produce symmetrically reduced ductions in both eyes. The reduction may be minimal or maximal. Ptosis, not shown here, is sometimes present.

103

Myasthenia Gravis Key Facts

SECTION 5 • Extraocular Muscle Disorders 104

• Autoimmune disorder that targets acetylcholine receptors in somatic muscles • Affects patients of any age and either gender • 50% present with ptosis, diplopia, and/or ductional deficits as isolated manifestations (ocular myasthenia) • 50% of ocular myasthenics will develop weakness of muscles of limb girdle, face, neck, mastication, swallowing, phonation, and breathing, usually within 2 years of ophthalmic manifestations • 90% of patients have ophthalmic manifestations at some time • Diagnosis based on clinical findings and confirmed with intravenous edrophonium chloride (Tensilon) test, repetitive stimulation and single-fiber electromyography (SFEMG), and assay of serum acetylcholine receptor antibodies (AChRAbs) • One or more ancillary studies is positive in 90% of cases • Ptosis and diplopia respond inadequately to acetylcholinesterase inhibitors (pyridostigmine) but often adequately to low-dose corticosteroids (prednisone 10–20 mg/day) • Involvement of autonomically innervated musculature (iris sphincter, ciliary body) does not occur

Clinical Findings • History of fluctuating ptosis or diplopia, often better after sleep and worse at end of the day • Ptosis in >75%—may be unilateral or bilateral and isolated, and it worsens with sustained upgaze • Incomitant misalignment or ductional deficits that do not suggest a third, fourth, or sixth cranial neuropathy • Bilateral orbicularis oculi weakness in >75% • Weakness of facial, neck, jaw, limb girdle muscles sometimes present • Difficulty sustaining speech, swallowing, or breathing may be reported (requires emergency evaluation, see below)

Ancillary Testing • Sleep test: a patient with ptosis may be invited to nap for 30 min—reduction in ptosis after sleep suggests myasthenia • Ice pack test: an ice pack is placed over the ptotic lid for 1–2 min—reduction in ptosis immediately after its removal suggests myasthenia • Edrophonium (Tensilon) test: reduction in ptosis within 1 min of injecting 2–5 mg suggests myasthenia • Improvement in ocular misalignment or worsening (paradoxical response) also suggests myasthenia • False positives (cranial base lesions) and false negatives occur in about 10% of Tensilon tests • AChRAbs: present in only 30–50% of ocular myasthenia (30–50% sensitivity) but not in non-myasthenic conditions (100% specificity) • Repetitive stimulation electromyography (EMG): a >10% decrease in amplitude of compound muscle action potential (decremental response) suggests myasthenia but occurs in only 30–50% of ocular myasthenics • Sensitivity is greater when orbicularis oculi muscles are tested • SFEMG: excessive jitter suggests myasthenia and is positive in 80% of ocular myasthenics • False positives may occur

A

Myasthenia Gravis

B

Fig. 5.5 Myasthenia gravis. (A) Left hypertropia in primary position and right upper lid ptosis. There is reduced infraduction of the left eye, reduced abduction of both eyes, and reduced abduction and supraduction of the right eye. (B) One minute after administration of intravenous edrophonium chloride (Tensilon), the eyes have regained normal position and full ductions and the ptosis has disappeared. Caution: myasthenia gravis may produce any ocular misalignment pattern; administration of intravenous edrophonium chloride often does not fully resolve the deficits.

105

Myasthenia Gravis (Continued) • One or more ancillary tests will be positive in 90% • A reasonable diagnostic approach: • start with AChRAb testing; if positive, the diagnosis is affirmed; if not, perform Tensilon test in younger patients • in older patients and those with equivocal Tensilon test results, perform EMG and SFEMG

Differential Diagnosis


• • • • • • • •

Genetic extraocular myopathy Graves disease Orbital myositis Ptosis of previous trauma, surgery, or inflammation Ocular motor cranial nerve palsy Fisher syndrome (variant of Guillain–Barré syndrome) Chronic inflammatory demyelinating polyradiculoneuropathy Conversion from a congenital latent to a manifest comitant misalignment (decompensating phoria) • Skew deviation • Internuclear ophthalmoplegia

Treatment • Patients whose ptosis or diplopia is not troublesome and who have no other myasthenic signs do not need treatment • Pyridostigmine (60–240 mg every 3–6 h), a cholinesterase inhibitor, is often effective for non-ophthalmic manifestations but less effective for ophthalmic manifestations • Prednisone 5–20 mg/day is often effective for ptosis and diplopia • Corticosteroid-sparing agents such as mycophenolate mofetil may be useful if chronic prednisone doses >20 mg/day are needed for palliation • Plasmapheresis or intravenous immunoglobulin treatment is reserved for debilitating signs • The value of thymectomy is still unproven—it is not usually indicated in ocular myasthenia because it is invasive • For refractory and stable (at least 1 year) ocular misalignment, surgical realignment of the eyes can be attempted

Prognosis • Ptosis and diplopia can usually be adequately palliated with low-dose prednisone with or without pyridostigmine or a corticosteroid-sparing agent • Spontaneous remissions occur in 20% of patients

106

Section 6 Single Ocular Motor Cranial Nerve Disorders Third Cranial Nerve Palsy

110

Fourth Cranial Nerve Palsy

112

Sixth Cranial Nerve Palsy

114

Third Cranial Nerve Palsy Key Facts • Damage to third cranial nerve causing reduced adduction, supraduction, infraduction, ptosis, and/or mydriasis with reduced constriction to light • Common causes: • reduced perfusion to intracranial segment of the nerve in diabetes or arteriosclerosis (ischemic palsy) • compression by intracranial aneurysm or other mass lesions • head trauma • meningitis • Most urgent rule-out diagnosis: intracranial aneurysm • Brain MRI/magnetic resonance angiography or CT/CT angiography, indicated in nearly all cases, will be negative in ischemic palsy but will usually detect an aneurysm

Clinical Findings • Any combination of deficits in adduction, supraduction, infraduction, ptosis, and/ or mydriasis with reduced constriction to light • No other manifestations need be present (isolated palsy)

SECTION 6 • Single Ocular Motor Cranial Nerve Disorders

Ancillary Testing • MRI/magnetic resonance angiography or CT/CT angiography in all patients except when the evidence for an ischemic palsy is overwhelming, as in: • older adult • arteriosclerotic risk factors • complete ductional deficits and ptosis • complete sparing of pupil • no history to suggest an underlying pertinent systemic disease • When interpreted by an experienced radiologist, brain MRI and CT angiography are nearly 100% sensitive to brain aneurysm causing third cranial nerve palsy • When suspicion for aneurysm is high and non-invasive imaging is negative, catheter cerebral angiography should be done • If intracranial studies are negative, consider body imaging to rule out occult systemic inflammatory or neoplastic disorder • If no recovery within 3 months, perform brain MRI


Graves disease Orbital myositis Orbital tumor Traumatic orbitopathy Myasthenia gravis Fourth cranial nerve palsy Internuclear ophthalmoplegia Skew deviation

Treatment • Extraocular muscle surgery if: • palsy stable for ≥9 months • some adduction, supraduction, and infraduction are present • For patients who are not surgical candidates or who have failed extraocular muscle surgery, consider a monocular occluding (painted) contact lens if diplopia is troublesome

Prognosis 110

• For ischemic palsies, resolution is complete and occurs within 3 months • For non-ischemic palsies, resolution depends on underlying process

A

Third Cranial Nerve Palsy

Fig. 6.1 Right third cranial nerve palsy. The right eye displays complete ptosis, a dilated pupil, and absent adduction, supraduction, and infraduction. The left eye is normal. This is a complete third cranial nerve palsy; incomplete forms, which are more common, may partially or completely spare the eyelid, the pupil, and some ocular ductions.

B

C

Fig. 6.2 Aneurysmal third cranial nerve palsy. (A) Cerebral angiogram shows aneurysm arising from internal carotid artery at its junction with the posterior communicating artery (arrow). Not shown is its compression of the third cranial nerve. (B) A three-dimensional reconstruction based on the angiogram also shows the aneurysm (arrow). (C) After coiling, the aneurysm no longer fills with contrast dye (arrow).

111

Fourth Cranial Nerve Palsy Key Facts • Damage to fourth cranial nerve causing vertical misalignment that increases with gaze contralateral to side of palsy and with ipsilateral head tilt • Common causes: • reduced perfusion to intracranial segment of the nerve in diabetes or arteriosclerosis (ischemic palsy) • head trauma • decompensation of a congenital fourth cranial nerve palsy • Uncommon causes: • compression by intracranial mass lesions • non-infectious, infectious, or neoplastic meningitis • Brain MRI indicated if an ischemic palsy is not a plausible diagnosis

Clinical Findings


• Vertical diplopia sometimes with torsional misalignment of images • Vertical misalignment that increases with gaze contralateral to side of palsy and with ipsilateral head tilt • Excyclodeviation on double Maddox rod test (>10º suggests bilateral fourth cranial nerve palsies) • Increased vertical fusional amplitudes suggest decompensated congenital disorder

Ancillary Testing • Intravenous edrophonium chloride test, repetitive stimulation and single-fiber electromyography, and/or acetylcholine receptor antibodies are indicated if myasthenia gravis is a consideration • Orbit imaging if there are clinical signs of orbitopathy • MRI/magnetic resonance angiography or CT/CT angiography indicated if ischemic palsy is not a plausible diagnosis


Graves disease Orbital myositis Orbital tumor Traumatic orbitopathy Myasthenia gravis Third cranial nerve palsy Skew deviation

Treatment • In palsy stable for ≥9 months, consider extraocular muscle surgery

Prognosis • Ischemic palsies resolve completely within 3 months • Non-ischemic palsies have variable resolution depending on cause and degree of damage • Extraocular muscle surgery is nearly always successful in providing an adequate zone of single binocular vision 112

A

Fig. 6.3 Right fourth cranial nerve palsy. In primary position (straight ahead gaze), the right eye is higher than the left eye (right hypertropia). In right gaze and left head tilt, the hypertropia diminishes; in left gaze and right head tilt, the hypertropia increases (head tilts shown in B).

Fourth Cranial Nerve Palsy

B

113

Sixth Cranial Nerve Palsy Key Facts


• Damage to sixth cranial nerve causing incomitant esodeviation with or without abduction deficit • Common causes: • reduced perfusion to the intracranial segment of the nerve in diabetes or arteriosclerosis (ischemic palsy) • head trauma • Uncommon causes: • compression by intracranial mass lesions • non-infectious, infectious, or neoplastic meningitis • increased intracranial pressure (false-localizing sixth cranial nerve palsy) • multiple sclerosis • other brain stem disorders • Most urgent rule-out diagnosis: increased intracranial pressure • Bilateral simultaneous sixth cranial nerve palsies are never caused by ischemia but by: • increased intracranial pressure • meningeal inflammation or neoplastic infiltration • clival or pontine tumors • Brain MRI indicated if ischemic palsy is not a plausible diagnosis

Clinical Findings • Incomitant esodeviation with or without abduction deficit • No other manifestations need be present (isolated palsy) • If papilledema is present, may be a false-localizing sign secondary to increased intracranial pressure causing downward displacement of the brain and tugging on the sixth cranial nerve

Ancillary Testing • MRI indicated unless ischemic palsy is a very likely diagnosis • If MRI is negative, lumbar puncture is indicated to rule out meningitis • If all studies are negative, body imaging may be indicated to rule out occult systemic inflammatory or neoplastic disorder • If all studies negative, presume ischemic or idiopathic inflammatory cause and advise monocular occlusion or spectacle prism • If no recovery within 3 months, repeat brain imaging

Differential Diagnosis • Myasthenia gravis • Graves disease • Orbital myositis • Orbital tumor • Traumatic orbitopathy • Duane syndrome • Divergence insufficiency • Spasm of the near reflex

Treatment • For palsies stable for ≥9 months, consider extraocular muscle surgery

Prognosis • Ischemic palsies: resolution is complete and occurs within 3 months • Non-ischemic palsies: recovery is variable and is complete within 9 months unless process is ongoing • Surgical realignment provides satisfactory zone of single binocular vision when there is some abduction preoperatively • when there is not, the patient may get single binocular vision in straight ahead and contralateral gaze but generally not in ipsilateral gaze

114

Sixth Cranial Nerve Palsy

Fig. 6.4 Right sixth cranial nerve palsy. In primary position, the eyes display esotropia. In right gaze, the right eye does not cross the midline. The left eye moves normally. This is a complete sixth cranial nerve palsy; incomplete forms, which are more common, display less obvious features.

115

Section 7 Multiple Ocular Motor Cranial Nerve Disorders Unilateral Ophthalmoplegia

118

Bilateral Ophthalmoplegia

120

Direct Carotid–cavernous Fistula

124

Indirect (Dural) Carotid–cavernous Fistula

126

Unilateral Ophthalmoplegia Key Facts • Uniocular ductional deficits that cannot be attributed to dysfunction of a single ocular motor cranial nerve • May also have ptosis, anisocoria and/or reduced pupil constriction to light, and reduced sensation or pain in distribution of trigeminal nerve • Lesion usually lies in orbit or cavernous sinus but may be multicentric • Common causes: • neoplasm • aneurysm • infection • inflammation • arteriovenous fistula

Clinical Findings

SECTION 7 • Multiple Ocular Motor Cranial Nerve Disorders

• Uniocular ductional deficits attributable to dysfunction of more than one ocular motor nerve • May have: • ptosis • anisocoria and/or reduced pupil constriction to light • reduced sensation or pain in distribution of trigeminal nerve • elevated intraocular pressure • proptosis • resistance to retropulsion • congested eyelids or conjunctiva

Ancillary Testing • CT adequate for suspected orbital disease, MRI best for retro-orbital disease • Infection, non-infectious inflammation, fistula, and neoplastic infiltration may produce subtle signs that go unnoticed even on high-grade MRI • Lumbar puncture often discloses evidence of neoplastic infiltration but may not be sensitive to indolent inflammation • Arteriovenous fistulas are visible on magnetic resonance angiography source images but catheter cerebral angiography still gold standard • For lesions originating in paranasal sinuses, biopsy often diagnostic • Imaging of chest, abdomen, and pelvis helpful in suspected metastatic or multicentric disease • Bone marrow biopsy helpful in suspected hematopoietic cancer


Graves disease Orbital myositis Orbital tumor Traumatic orbitopathy Myasthenia gravis Fisher syndrome

Treatment • Depends on process

Prognosis • Depends on process

118

Fig. 7.1 Right unilateral ophthalmoplegia. The right eye has ptosis and absent ductions in all directions. The left eye is normal.

Unilateral Ophthalmoplegia

Fig. 7.2 Right ophthalmoplegia from metastatic adenoid cystic carcinoma. Postcontrast coronal T1 MRI shows an enhancing mass in the right cavernous sinus (arrow).

119

Bilateral Ophthalmoplegia Key Facts • Binocular ductional deficits that cannot be attributed to dysfunction of a single ocular motor cranial nerve • May have ptosis, anisocoria and/or reduced pupil constriction to light, and reduced sensation or pain in distribution of trigeminal nerve • May have proptosis, resistance to retropulsion of eyes, and congested eyelids or conjunctiva • Lesions may lie in extraocular muscles, orbits, cavernous sinuses, basal meninges, brainstem, or cerebrum • Common causes: • bilateral orbital lesions • myasthenia gravis • Fisher syndrome • cavernous sinus lesions

Clinical Findings

SECTION 7 • Multiple Ocular Motor Cranial Nerve Disorders

• Binocular ductional deficits • May also have ptosis, pupil or trigeminal abnormalities, and orbital congestive features • Doll’s head maneuver enhances ductions in progressive supranuclear palsy and bilateral frontoparietal infarcts • Progressive supranuclear palsy: • parkinsonian features • neck rigidity • stance and gait instability • Fisher syndrome: • absent deep tendon reflexes • ataxia • Myasthenia gravis: • no pain • pupils normal • positive edrophonium • AChRAb and EMG tests (see above) • Botulism: • mydriasis • loss of accommodation • diarrhea or constipation • Pituitary apoplexy: • headache • bitemporal hemianopia • addisonian features • fever • meningismus • photophobia • Wernicke encephalopathy: • altered cognition • ataxia • Thalamic infarction or hemorrhage: • depressed consciousness • limb paralysis • ataxia • Bilateral frontoparietal infarcts: • doll’s head maneuver enhances ductions • patient unable to interpret visual arrays (simultanagnosia) or point accurately to objects (optic ataxia) • quadriparesis

Ancillary Testing • • • • • • • • •

120

Thalamic and frontoparietal infarcts: MRI shows lesions Myasthenia gravis: edrophonium, AChRAb, and EMG tests may be confirmatory Wernicke encephalopathy: MRI may show signal alterations in medial thalamus Paranasal sinus disease: MRI shows lesions; endoscopic biopsy, smear, and culture help in diagnosis Fisher syndrome: lumbar puncture shows high protein, nerve conduction studies may show slowed conduction, and antiganglioside antibody GQ1b often positive Bilateral orbital lesions: imaging and biopsy help in diagnosis Bilateral cavernous sinus lesions: lumbar puncture may show cells Botulism: stool sample reveals the toxin Whipple disease: Polymerase Chain Reaction (PCR) of spinal fluid shows organism and small intestine biopsy shows typical pathology

Fig. 7.3 Bilateral ophthalmoplegia. Both eyes have ptosis and absent ductions in all directions.

Bilateral Ophthalmoplegia

Fig. 7.4 Bilateral ophthalmoplegia from rhabdomyosarcoma originating in the nasopharynx. Postcontrast coronal T1 MRI shows enhancing masses in both cavernous sinuses (arrows).

121

Bilateral Ophthalmoplegia (Continued) Differential Diagnosis • • • • • • • • • • • • • • •

SECTION 7 • Multiple Ocular Motor Cranial Nerve Disorders 122

Graves disease Genetic extraocular myopathy Orbital myositis Orbital tumor Traumatic orbitopathy Bilateral cavernous sinus disease Bilateral paranasal sinus disease Myasthenia gravis Botulism Fisher syndrome Wernicke disease Thalamic infarct, hemorrhage, tumor Progressive supranuclear palsy Whipple disease Bilateral frontoparietal infarcts

Treatment • Thalamic and bilateral frontoparietal infarcts: supportive care • Wernicke disease: intravenous thiamine 100 mg • Fisher syndrome: plasmapheresis or intravenous immunoglobulin if severe or worsening, otherwise observe or use corticosteroids • Botulism: supportive care and antitoxin if necessary • Bilateral paranasal sinus disease: debridement and anti-infective drugs • Bilateral cavernous sinus disease: depends on cause • Pituitary apoplexy: corticosteroids, surgery

Prognosis • Thalamic disease: eye movements may recover but ataxia and extremity weakness usually permanent • Wernicke disease: eye movements recover but may have residual memory loss • Botulism: recovery usually complete if supportive care is prompt and adequate • Paranasal and cavernous sinus disease: depends on cause • Progressive supranuclear palsy: gradual decline in arousal level, ability to stand and walk, swallow, talk

Direct Carotid–cavernous Fistula Key Facts • Abnormal connection between intracavernous carotid artery and cavernous sinus venous plexus • Hole in cavernous carotid artery caused by trauma, atherosclerosis, or elastic tissue degeneration • Florid proptosis, eyelid swelling, corkscrew conjunctival injection and chemosis, ductional deficits, increased IOP, and/or retinal venous congestion (red-eyed shunt) • If fistula drains posteriorly, may have cranial neuropathies but no orbital congestion (white-eyed shunt) • Treat promptly by endovascular methods

Clinical Findings


• • • • • • •

Periocular pain, eyelid swelling, proptosis Arterialized corkscrew conjunctival injection, chemosis Diplopia, reduced ocular ductions Optic nerve dysfunction Elevated IOP Retinal vein engorgement, perivenous hemorrhages Pulse-synchronous bruit (whooshing sound)

Ancillary Testing • MRI or CT usually shows dilated superior ophthalmic vein and enlargement of extraocular muscles, but fistula may not be evident except on magnetic resonance angiography source images • On catheter angiography, internal carotid artery injection shows very premature appearance of dye in cavernous sinus and sometimes intracavernous carotid hole, aneurysm, or dysplasia


Graves disease Orbital myositis Orbital tumor Traumatic orbitopathy Other causes of cavernous sinus syndrome

Treatment • Should be closed by endovascular methods (coiling, stenting, trapping) if possible

Prognosis • With experienced interventionalists, can usually be successfully closed with tolerable risk

Fig. 7.5 Direct carotid–cavernous fistula. Hemorrhagic conjunctival chemosis reflects severe orbital venous hypertension.

A

Direct Carotid–cavernous Fistula

Fig. 7.6 Right direct carotid–cavernous fistula. The hyperemic optic disc and dilated retinal veins in the right eye reflect venous hypertension. This sign, which is not often present, increases the urgency of treatment.

B

Fig. 7.7 Direct carotid–cavernous fistula. (A) Early arterial phase catheter cerebral angiogram shows premature filling of cavernous sinus (arrow) and superior ophthalmic vein (arrow head). (B) After coils were deposited in the cavernous sinus (arrow), angiography shows that the fistula is closed and there is no retrograde flow in the superior ophthalmic vein.

125

Indirect (Dural) Carotid–cavernous Fistula Key Facts


• Abnormal connection between pericavernous dural arterial branches and cavernous venous plexus • Arises from opening of pre-existing shunt vessels, usually in postpartum or postmenopausal women • Congestive orbital and ocular features much less florid than in direct carotid– cavernous fistula • Patient may report hearing pulse-synchronous bruit but not as frequently as with direct carotid–cavernous fistula • Clinical features may disappear spontaneously as fistula closes or blood is rerouted • Endovascular treatment is indicated only for: • refractory pain • diplopia • optic neuropathy • vision-threatening elevation in IOP • unsightly congestion


Periocular pain, eyelid swelling, proptosis Arterialized corkscrew conjunctival injection Diplopia, reduced ocular ductions Optic nerve dysfunction Elevated IOP Retinal vein engorgement, perivenous hemorrhages Pulse-synchronous bruit (whooshing sound)

Ancillary Testing • MRI or perhaps CT usually shows dilated superior ophthalmic vein and enlargement of extraocular muscles, but fistula may not be evident except on source images • Selective dye injection of external carotid artery often shows multiple dilated feeder vessels and premature appearance of dye in cavernous sinus


Graves disease Orbital myositis Orbital tumor Chronic conjunctivitis

A

Fig. 7.8 (A) Preoperative photograph of a patient with an indirect (dural) carotid–cavernous fistula shows lid and conjunctival edema with engorged conjunctival vessels. (B) After closure of the fistula (see Fig 7.9), congestive features have disappeared.

Indirect (Dural) Carotid–cavernous Fistula

B

127

Indirect (Dural) Carotid–cavernous Fistula (Continued) Treatment • Observe for spontaneous closure for several months unless patient has refractory pain, uncontrollably high IOP, or vision-threatening optic neuropathy • For IOP >30, use pressure-lowering agents • Attempt endovascular closure only if spontaneous improvement has not occurred for several months and patient has refractory pain, diplopia, optic neuropathy, vision-threatening elevation in IOP, or unsightly congestion

Prognosis • Spontaneous closure of fistula occurs in about 50% • Indirect fistulas may be difficult to close if there are multiple feeders; several procedures may be required but risks are generally tolerable


A

C

Indirect (Dural) Carotid–cavernous Fistula (continued)

B

Fig. 7.9 Lateral views of cerebral angiogram of patient in Fig. 7.8. (A) Pretreatment common carotid angiogram shows early dye filling of the cavernous sinus (arrow) and superior ophthalmic vein (arrowhead). (B) Pretreatment selective external carotid angiogram shows tiny arterial feeders of the fistula (black arrows) and early filling of the cavernous sinus (white arrows). (C) Post-treatment common carotid angiogram shows that the cavernous sinus no longer fills with dye because the sinus has been filled with coils (arrows).

129

Section 8 Brainstem Ocular Motor Disorders Internuclear Ophthalmoplegia

132

Skew Deviation

134

Dorsal Midbrain (Pretectal) Syndrome

136

Paramedian Thalamic or Midbrain Syndrome

138

Paramedian Pontine Syndrome

140

Dorsolateral Medullary (Wallenberg) Syndrome

142

Acute Upgaze Deviation

144

Acute Downgaze Deviation

146

Acute Convergence Syndrome (Acute Comitant Esotropia)

148

Omnidirectional Slow Saccades

150

Omnidirectional Saccadic Pursuit

152

Internuclear Ophthalmoplegia Key Facts • Adduction weakness caused by interruption of neural transmission within medial longitudinal fasciculus • Jerk nystagmus of abducting fellow eye often present • Vertical misalignment (skew deviation) often present • Saccadic pursuit, ipsilateral gaze palsy (one and a half syndrome), and ataxia may occur • Lesion lies in cerebellum, pons, or midbrain • Common causes: • ischemic stroke in older adults • multiple sclerosis in younger adults or children • Other causes: • head trauma • brainstem or cerebellar tumor or hemorrhage • neurodegenerative, toxic, or metabolic disorders

SECTION 8 • Brainstem Ocular Motor Disorders

Clinical Findings • • • • • •

Deficit ranges from adduction slowing (with full adduction) to absent adduction Jerk nystagmus in abduction of fellow eye is common but not obligatory Eyes may be aligned in primary position or show exodeviation Vertical misalignment (skew deviation) is common Saccadic pursuit is common Eye findings may be accompanied by ataxia or extremity weakness and numbness

Ancillary Testing • Brain imaging may be normal if the cause is brainstem ischemic stroke, demyelination, or other inflammation, toxic, or metabolic disorders • Brain MRI readily identifies brainstem or cerebellar tumors or hemorrhages


Myasthenia gravis Third cranial nerve palsy Orbital myositis Traumatic orbitopathy Orbital tumor

Treatment • Because eyes are often aligned in primary position, diplopia is usually not debilitating • For primary position misalignment, extraocular muscle surgery can be performed if condition is stable for at least 1 year

Prognosis • Often remits if caused by acute demyelination • Sometimes remits if caused by brainstem stroke (depending on severity) • Surgical realignment often successful in palliating primary gaze diplopia

132

Fig. 8.1 Right internuclear ophthalmoplegia. In primary position, the eyes are aligned, but in left gaze the right eye does not fully adduct. The left eye moves normally.

Internuclear Ophthalmoplegia

Fig. 8.2 Axial T2 MRI shows high signal in the right pons at the floor of the fourth ventricle and in the region of the medial longitudinal fasciculus (arrow).

133

Skew Deviation Key Facts • Vertical misalignment caused by unilateral (or bilaterally asymmetric) interruption of neural connections between semicircular canals and ocular motor nuclei • Misalignment may be comitant or incomitant • Saccadic pursuit, nystagmus, internuclear ophthalmoplegia, gaze paresis, or ataxia often present • Lesion usually lies in brainstem but may rarely be in semicircular canals or vestibular nerve • Common causes: • brainstem ischemic or hemorrhagic stroke • brainstem or cerebellar tumor • multiple sclerosis • Other causes: neurodegenerative, infectious, and toxic or metabolic disorders

Clinical Findings


• Vertical misalignment that may be comitant or incomitant • Can usually be distinguished from fourth cranial nerve palsy by lack of positivity on three-step test and lack of excyclotorsion on double Maddox rod test • Other signs often present: • saccadic pursuit • nystagmus • internuclear ophthalmoplegia • gaze paresis • limb, gait, or speech ataxia

Ancillary Testing • MRI readily identifies brainstem or cerebellar tumors or hemorrhages but may be normal in brainstem stroke, demyelination, or other inflammation


Third cranial nerve palsy Fourth cranial nerve palsy Myasthenia gravis Orbital myositis Graves disease Traumatic orbitopathy Orbital tumor

Treatment • May be able to eliminate diplopia with a Fresnel or ground-in spectacle prism • In unremitting skew deviation, extraocular muscle surgery is an option

Prognosis • Skew deviation may spontaneously remit if brainstem lesion is demyelinative or otherwise mild • Extraocular muscle surgery may fail to provide an adequate zone of single binocular vision if patient lacks fusional ability

134

Skew Deviation

Fig. 8.3 Skew deviation. In all gaze positions, the right eye is higher than the left eye (right hypertropia). In skew deviation, the eyes are always vertically misaligned. The degree of misalignment may be the same (comitant) or different (incomitant) as gaze positions change.

Fig. 8.4 Skew deviation in pontine glioma. Axial FLAIR MRI shows diffuse high signal in the pons (arrow).

135

Dorsal Midbrain (Pretectal) Syndrome Key Facts • Impaired vertical gaze but intact horizontal gaze • Markedly impaired upgaze often with convergence–retraction movements of eyes • Dilated pupils that constrict poorly to light but briskly to a near target (see Tectal (Dorsal Midbrain) Pupils) • Common causes: • ischemic stroke • demyelination • hydrocephalus • pineal region tumor

Clinical Findings • Markedly impaired upgaze • Lid retraction (Collier sign) • Convergence– retraction of eyes with attempted upgaze • Dilated pupils that constrict poorly to light but briskly to a near target • With more ventral lesion, may also have: • impaired pupil constriction to a near target • impaired downgaze • exotropia • esotropia • skew deviation • torsional nystagmus • Doll’s head maneuver may enhance vertical eye movement

SECTION 8 • Brainstem Ocular Motor Disorders 136

Ancillary Testing • MRI shows pertinent abnormalities in brainstem or diencephalic stroke and pineal region tumor, and sometimes in hydrocephalus and multiple sclerosis

Differential Diagnosis • Myasthenia gravis • Graves disease • Orbital myositis • Orbital tumor • Traumatic orbitopathy • Progressive supranuclear palsy • Whipple disease

Treatment • Stroke: supportive care • Pineal region tumor: biopsy and radiation or chemotherapy • Demyelination: consider immunomodulatory agents • Decompensated hydrocephalus: ventriculoperitoneal or third ventricular shunt

Prognosis • Findings often disappear within weeks in mild stroke or demyelination but may be permanent in other conditions

Fig. 8.5 Dorsal midbrain (pretectal) syndrome. In primary position, both eyes are deviated slightly downward. They are not vertically aligned. With attempted upgaze, the eyes do not ascend above the midline and they often converge and retract repeatedly (see Convergence–retraction “nystagmus”). The pupils are larger than normal; they do not constrict to light but may constrict to a near target (see Tectal [dorsal midbrain] pupils).

B

C

D

Fig. 8.6 Pineal germinoma. (A) Axial FLAIR MRI shows high-signal round mass (arrow) in pineal region. (B) Image at midbrain level shows high signal in the dorsal midbrain (arrow), indicating infiltration or injury. Biopsy showed germinoma. Axial FLAIR MRI 1 year after systemic chemotherapy and whole brain radiation shows that pineal region tumor has vanished (C, arrow) and dorsal midbrain signal is now normal (D, arrow).

Dorsal Midbrain (Pretectal) Syndrome

A

137

Paramedian Thalamic or Midbrain Syndrome Key Facts • • • •

Upgaze and downgaze palsy with preserved horizontal gaze May have comitant esotropia, exotropia, or hypertropia May have unilateral or bilateral third cranial nerve palsy Common causes: • occlusion of proximal branch of posterior cerebral artery (top of the basilar syndrome) • thalamic or midbrain hemorrhage • pineal region tumor • acute hydrocephalus • head trauma • demyelination • radiation


Upgaze and downgaze palsies and sometimes third cranial nerve palsy Sometimes torsional nystagmus Esotropia, exotropia, or hypertropia Often hypersomnolence Often ataxia


Ancillary Testing • Ischemic stroke: MRI may show restricted diffusion in one or both sides of paramedian thalamus and in paramedian midbrain • Thalamic or midbrain hemorrhage: MRI and CT will show blood • Hydrocephalus: MRI and CT show dilated lateral and third ventricles • Thalamic, midbrain, or pineal tumor: MRI and CT show the mass

Differential Diagnosis • • • • • • • • •

Thalamic–midbrain ischemic stroke Thalamic–midbrain hemorrhage Head trauma Midbrain tumor Thalamic tumor Pineal tumor Hydrocephalus Demyelination Brain radiation

Treatment • • • • • • •

Cardiogenic embolism: warfarin anticoagulation Non-embolic ischemic stroke: supportive care Thalamic or midbrain hemorrhage: supportive care, control blood pressure Hydrocephalus: address need for shunt or repair of shunt malfunction Thalamic, midbrain, or pineal tumor: biopsy, chemotherapy, radiation Demyelination: evaluate for multiple sclerosis Radiation: supportive care

Prognosis • Depends on underlying lesion • In ischemic stroke and hemorrhage, hypersomnolence usually resolves within weeks • Ocular motor manifestations improve more than ataxia

138

A

B

C

Fig. 8.8 Paramedian thalamic and midbrain infarction (top of the basilar syndrome). Axial diffusion-weighted MRI at (A) thalamic and (B) midbrain levels shows restricted diffusion (bright signal) in paramedian regions bilaterally (arrows). (C) Drawing shows how occlusion of proximal branches of the posterior cerebral artery produce these kinds of infarcts. (After Trobe JD. The Neurology of Vision. New York: Oxford University Press; 2001: 304, with permission.)

A

Paramedian Thalamic or Midbrain Syndrome

Fig. 8.7 Paramedian thalamic and midbrain (top of the basilar) syndrome. Eyes display the features of a dorsal midbrain (pretectal) syndrome. In addition, downgaze is absent or impaired. This is only one variant of the many ocular misalignment and motility manifestations caused by lesions in this region.

B

Fig. 8.9 Paramedian thalamic infarction (top of the basilar syndrome). (A) Axial FLAIR MRI and (B) diffusion-weighted MRI show bilateral paramedian thalamic infarcts (arrows).

139

Paramedian Pontine Syndrome Key Facts • Impaired ipsilateral horizontal gaze and impaired adduction of ipsilateral eye (one and a half syndrome) • May have ipsilateral gaze deviation (see Acute horizontal gaze deviation) • Intact vertical gaze • Common causes: • stroke • demyelination • tumor • vascular malformation • myelinolysis

Clinical Findings


• Impaired ipsilateral horizontal gaze and impaired adduction of ipsilateral eye (one and a half syndrome) • Intact vertical gaze • Associated findings: • exotropia with contralateral eye deviated outward (pontine exotropia) • vertical misalignment (skew deviation) • nystagmus • saccadic pursuit • Pupils are normal • Doll’s head maneuver fails to elicit normal eye movements

Ancillary Testing • MRI detects tumor, myelinolysis, and vascular malformation, but only sometimes detects stroke and multiple sclerosis


Myasthenia gravis Fisher syndrome Wernicke encephalopathy Frontoparietal infarct

Treatment • • • • • •

Stroke: supportive care Tumor: search for primary site, lumbar puncture Vascular malformation: radiation or surgery, as appropriate Multiple sclerosis: immunomodulatory agents Fisher syndrome: plasmapheresis or intravenous immunoglobulin Wernicke encephalopathy: thiamine

A

Paramedian Pontine Syndrome

Fig. 8.10 Right paramedian pontine syndrome. The eyes display a left exotropia in primary position. In right gaze, neither eye crosses the midline. In left gaze, the right eye does not cross the midline and the left eye has a normal excursion. This pattern is called a one and a half syndrome, one of the manifestations of paramedian pontine dysfunction.

B

Fig. 8.11 Cavernous hemangioma of the left pons. (A) Axial FLAIR MRI shows a round mass (arrow) in the left paramedian pons with inhomogenous signal. (B) After surgical extirpation, the mass (arrow) is much smaller.

141

Dorsolateral Medullary (Wallenberg) Syndrome Key Facts • Acute onset vertical diplopia, oscillopsia, ipsilateral ptosis and miosis (Horner syndrome), imbalance, severe nausea and vomiting, hoarseness, and swallowing difficulty • Caused by infarction in domain of posterior inferior cerebellar artery from arteriosclerosis or dissection in vertebral artery • MRI shows infarction in dorsolateral medulla and sometimes inferolateral cerebellar hemisphere • Intensive care monitoring necessary because of early risk of aspiration • Full recovery common but takes months

Clinical Findings


• Hypertropia (skew deviation), ipsilateral ptosis and miosis (Horner syndrome), torsional nystagmus • Under closed lids, eyes deviate horizontally to side of lesion, saccades toward side of lesion are hypermetric, and saccades away from lesion are hypometric (ocular lateropulsion) • Non-ophthalmic findings: • ataxia • nausea and vomiting • hoarseness and swallowing difficulty • ipsilateral trigeminal hypesthesia • contralateral extremity hypesthesia

Ancillary Testing • MRI shows restricted diffusion in dorsolateral medulla and sometimes inferolateral cerebellar hemisphere within first week • May also show blood in vertebral artery wall if there has been a dissection • Magnetic resonance angiography may show narrowing or occlusion of ipsilateral vertebral artery

Differential Diagnosis • Cerebellar hemorrhage or tumor • Multiple sclerosis

Treatment • Needs intensive monitoring within first 48 h because of risk of aspiration • Consider short-term anticoagulation if vertebral dissection is proven by imaging • Palliative care for vertigo, intractable vomiting and hiccupping, swallowing difficulty • Physical therapy for ataxia • Occlusion, prism for diplopia of skew deviation

Prognosis • Recovery is prolonged and some deficits may persist

142

A

B

Fig. 8.13 (A) Axial T2 MRI shows high signal in the right dorsolateral medulla (arrow) and inferomedial cerebellar hemisphere (arrowheads), indicating infarction in the territory supplied by the posterior inferior cerebellar artery. (B) MRA shows absence of signal in expected location of right vertebral artery which has been occluded by dissection (arrowheads).

Dorsolateral Medullary (Wallenberg) Syndrome

Fig. 8.12 Right dorsolateral medullary (Wallenberg) syndrome. There is mild right upper lid ptosis and miosis (Horner syndrome). The left eye is higher than the right eye (left hypertropia; see Skew deviation). In left gaze, the eyes display a clockwise rotary jerk nystagmus.

143

Acute Upgaze Deviation Key Facts • Sudden sustained involuntary upgaze; may occur in episodes • In neonates, may be isolated benign disorder that resolves completely • May also be part of: • syncope • generalized seizure • dystonic reaction to neuroleptics (oculogyric crisis) • carbamazepine toxicity • hypoxic encephalopathy • habit spasm (tic)

Clinical Findings


• • • • •

Sustained upgaze No other ophthalmic abnormalities Syncope: loss of consciousness follows upgaze, with full recovery within minutes Seizure: expect tonic–clonic extremity movements and loss of consciousness Oculogyric crisis: dystonic facial and/or extremity postures, altered thoughts or emotions • Carbamazepine toxicity: ataxia • Hypoxic encephalopathy: twitching of extremities (asterixis) • Habit spasms: involuntary movements of face or extremities

Ancillary Testing • MRI useful to rule out mass lesions • Serum carbamazepine levels may be elevated • If unexplained syncope occurred, perform work-up for its causes


Syncope Oculogyric crisis Carbamazepine toxicity Seizure Transient idiopathic benign condition of infants

Treatment • Depends on underlying condition


144

Fig. 8.14 Upgaze deviation. In all gaze positions, both eyes are upwardly deviated.

Acute Upgaze Deviation 145

Acute Downgaze Deviation Key Facts • Sudden sustained downward deviation of eyes • Voluntary and reflex upgaze absent • Common causes: • temporary idiopathic disorder in otherwise normal neonates • seizure • upper brainstem hemorrhage or infarct • obstructive hydrocephalus • hepatic encephalopathy

Clinical Findings


• Sudden sustained downgaze • Doll’s head maneuver fails to elicit normal vertical eye movements • May have: • impaired consciousness • irritability • vomiting • papilledema • esotropia • May have other manifestations of a seizure

Ancillary Testing • MRI may show thalamic or dorsal midbrain lesions, ventriculomegaly, or other congenital malformations • Electroencephalogram may show signs of epilepsy • Abnormal liver chemistries and serum ammonia suggest hepatic encephalopathy


Thalamic or dorsal midbrain lesion Obstructive hydrocephalus Hepatic encephalopathy Benign transient condition in neonates

Treatment • Depends on process

Prognosis • Depends on process

146

Fig. 8.15 Downgaze deviation. In all gaze positions, both eyes are downwardly deviated.

Acute Downgaze Deviation

Fig. 8.16 Axial FLAIR MRI shows enlarged lateral ventricles in a patient with acute shunt malfunction. When intracranial pressure suddenly went up, the eyes went down (sunset sign). Caution: ventricles do not often enlarge in acute shunt malfunction, so the diagnosis must be made in other ways.

147

Acute Convergence Syndrome (Acute Comitant Esotropia) Key Facts • Sudden sustained comitant esotropia with diplopia • If an isolated sign, may be caused by loss of binocular fusion in an otherwise healthy patient • If combined with disturbance of consciousness or cognition, may be manifestation of fusion loss caused by: • increased intracranial pressure • metabolic encephalopathy • meningoencephalitis • sedating medication • If combined with ataxia, weakness, numbness, and/or decreased consciousness, may be caused by thalamic or midbrain lesion

Clinical Findings


• • • • • •

Diplopia Comitant esotropia for distance viewing, eyes often aligned for near viewing Ocular ductions usually normal Papilledema may be present May have alterations in cognition or consciousness May have other signs of midbrain dysfunction (ataxia, weakness, numbness)

Ancillary Testing • MRI may be normal or show ventriculomegaly or a cerebellar, thalamic, or midbrain lesion, meningitis, or subarachnoid hemorrhage • Lumbar puncture may show elevated opening pressure or abnormal constituents, suggesting meningitis or subarachnoid hemorrhage

Differential Diagnosis • Decompensated esophoria unassociated with neurologic disease (primary decompensated esophoria) • Increased intracranial pressure, metabolic encephalopathy, meningoencephalitis, or sedating medication • Thalamic or midbrain lesion • Spasm of the near reflex • Bilateral sixth cranial nerve palsies

Treatment • Depends on underlying cause

Prognosis • Depends on underlying cause

148

Fig. 8.17 Acute convergence syndrome. In all positions of gaze, the eyes are convergently misaligned. Ductions are full.

B

Fig. 8.18 Rapidly enlarging glioblastoma multiforme causes mass effect and secondary breakdown of binocular fusion, leading to acute convergence syndrome. Postcontrast (A) sagittal and (B) axial T1 MRIs show a ring-enhancing mass that is displacing the brain.

Acute Convergence Syndrome (Acute Comitant Esotropia)

A

149

Omnidirectional Slow Saccades Key Facts • Very slow refixational eye movements in both eyes in all directions • In alert patients, usually caused by damage to saccadic generator in the pons • Common causes: • multiple sclerosis • pontine infarction • spinocerebellar ataxias (especially type 2) • progressive supranuclear palsy • genetic extraocular myopathies

Clinical Findings • Very slow saccadic eye movements in both eyes in all directions • In neurodegenerative conditions, may also find: • saccadic intrusions • nystagmus • skew deviation • esotropia • cognitive decline • parkinsonism • spasticity • dysautonomia

Ancillary Testing


• MRI shows brainstem atrophy in some neurodegenerative states, orbital signs in orbitopathies, but is normal in genetic extraocular myopathies • Blood for genetic testing of inherited ataxias • Muscle biopsies for mitochondrial myopathies • Serum for phenytoin level • PCR for Whipple antigen

Differential Diagnosis • Common causes: • multiple sclerosis • pontine infarction • spinocerebellar ataxias (especially type 2) • progressive supranuclear palsy • genetic extraocular myopathies • Uncommon causes: • Friedreich ataxia • Huntington disease • phenytoin toxicity • Whipple disease • paraneoplastic syndromes • ocular motor cranial nerve palsies • Fisher syndrome • myasthenia gravis • multiple system atrophies • Graves disease • orbital myositis • orbital trauma • Also consider sedative medication, psychogenic lack of cooperation



150

Fig. 8.19 Omnidirectional slow saccades. When the patient attempts refixational movements, the eyes move very slowly (indicated by dotted lines).

Omnidirectional Slow Saccades

Fig. 8.20 Hereditary cerebellar degeneration. Axial FLAIR MRI shows severe atrophy of the cerebellar folia (arrow).

151

Omnidirectional Saccadic Pursuit Key Facts • As the eyes follow a moving target, their movement is fragmented by fast catchup movements • Found in very elderly, inattentive, tired, sedated, and sleepy patients • Otherwise a sensitive but non-specific sign of brain dysfunction • Prominent finding in cerebellar disorders

Clinical Findings • Small jerky eye movements (saccades) replace smooth tracking movements (pursuit) when the patient is asked to follow a target moving at <40º/s in any direction

Ancillary Testing • MRI often negative in degenerative, toxic, metabolic, or inattentive states


Differential Diagnosis • Toxic, metabolic, or degenerative encephalopathy • Poor attention



Fig. 8.21 Omnidirectional saccadic pursuit. When the eyes follow a moving target, they fall behind and must catch up by using saccades (indicated by dashed lines).

Omnidirectional Saccadic Pursuit 153

Section 9 Cerebral Gaze Disorders Congenital Ocular Motor Apraxia

156

Acquired Ocular Motor Apraxia (Supranuclear Gaze Palsy)

158

Acute Horizontal Gaze Deviation

160

Spasm of the Near Reflex

162

Ping Pong Gaze

164

Congenital Ocular Motor Apraxia Key Facts • Horizontal eye movement disorder identified within first year of life • Horizontal voluntary eye movements (saccades and pursuit) are absent but reflex (vestibulo-ocular) horizontal eye movement is intact (ocular motor apraxia) • All vertical eye movements are intact • Child blinks and thrusts head in direction of intended horizontal gaze • Usually a form of delayed maturation of brain, with spontaneous recovery by second decade, but may be associated with other developmental, progressive metabolic, or degenerative neurologic conditions

Clinical Findings

SECTION 9 • Cerebral Gaze Disorders

• Horizontal saccades and pursuit are impaired or absent but vestibulo-ocular reflex, tested with doll’s head maneuver, is intact • All vertical eye movements are intact • Child blinks and thrusts head in direction of intended horizontal gaze • Developmental delay is common • Other neurologic deficits may be present

Ancillary Testing • Brain imaging usually normal but may show: • midline dysgeneses • signs of perinatal ischemia • heterotopias • Metabolic screening indicated if there are other neurologic abnormalities

Differential Diagnosis • Head thrusts may be misinterpreted as part of an involuntary movement disorder • Myasthenia gravis • Genetic extraocular myopathy

Treatment • None

Prognosis • If the ocular motor apraxia is an isolated finding, patients spontaneously recover normal eye movements by second decade

156

A

C

Fig. 9.1 (A) A patient is unable to generate any horizontal eye movements to command, either by saccades or pursuit. (B) When the patient wishes to look at a target to his right, he thrusts his head toward the right. This thrust elicits a contraversive reflex binocular eye movement to the left, which places his eyes to the left of the target he intends to view. (C) He moves his head slowly to the left, eliciting a reflex binocular eye movement to the right in order to place his eyes on the target. When reflex eye movements are more ample than volitional eye movements, the disorder is called apraxic or supranuclear.

Congenital Ocular Motor Apraxia

B

157

Acquired Ocular Motor Apraxia (Supranuclear Gaze Palsy) Key Facts • Acquired loss of all voluntary eye movements (saccades and pursuit) with preserved reflex eye movements (ocular motor apraxia) • Also called a supranuclear gaze disorder • Doll’s head maneuver elicits reflex eye movements by drawing on intact vestibulo-ocular reflex • Common causes: • progressive supranuclear palsy (PSP) • bilateral frontoparietal infarcts • Alzheimer disease

Clinical Findings


• Voluntary saccades and pursuit in all planes are reduced or absent • Doll’s head maneuver extends amplitude of horizontal and/or vertical gaze • Other neurologic manifestations: • impaired visuospatial function (Alzheimer disease, frontoparietal infarcts) • ataxia (ataxia telangiectasia) • rigidity • masked facies (PSP) • cognitive decline (Niemann–Pick disease type C) • pendular convergence nystagmus and rhythmic twitching of masticatory and limb muscles (Whipple disease) • memory loss (Alzheimer disease) • Non-neurologic manifestations: • visceromegaly (Niemann–Pick type C) • blepharitis (PSP) • diarrhea (Whipple disease) • sinopulmonary infections (ataxia telangiectasia)

Ancillary Testing • PSP: brain imaging may be normal or show atrophy of superior colliculus, low T2 signal in putamen (iron deposition) • Ataxia telangiectasia: superior cerebellar vermis atrophy • Bilateral frontoparietal infarcts: MRI signal abnormalities in affected brain regions • Whipple disease: small bowel biopsy for periodic acid Schiff positivity in macrophages or PCR test for Tropheryma whippelii DNA in spinal fluid • Neimann–Pick type C: bone marrow biopsy for sea-blue histiocytes, foam cells

Differential Diagnosis • PSP • Bilateral frontoparietal infarcts • Alzheimer disease • Ataxia telangiectasia • Niemann–Pick disease type C • Whipple disease • Wilson disease • Psychogenic lack of cooperation

Treatment • • • • • •

PSP: supportive care Ataxia telangiectasia: supportive care, treat infections as they develop Bilateral frontoparietal infarcts: supportive care Whipple disease: intravenous ceftriaxone or trimethoprim–sulfamethoxazole Niemann–Pick type C: supportive care Wilson disease: tetrahydromolybdate

Prognosis • Depends on condition 158

A

Fig. 9.2 (A) A patient is unable to generate any horizontal or vertical eye movements to command, either by saccades or pursuit. (B) Passive movement of the patient’s head (doll’s head maneuver) elicits contraversive reflex eye movements. Two differences between congenital and acquired ocular motor apraxia are: 1, in the congenital form, volitional gaze palsy is limited to the horizontal plane; 2, in the acquired form, head thrusts are not common. Fig. 9.3 Acquired ocular motor apraxia caused by bilateral frontoparietal infarcts. Diffusion-weighted MRI discloses high signal areas in the watershed frontoparietal regions bilaterally (arrows) in a patient who developed severe systemic hypotension during heart transplant surgery.

Acquired Ocular Motor Apraxia (Supranuclear Gaze Palsy)

B

159

Acute Horizontal Gaze Deviation Key Facts • Sudden onset of sustained horizontal gaze deviation • Caused by ipsilateral frontoparietal or contralateral pontine infarct or hemorrhage • Frontoparietal lesion: patient has contralateral hemiparesis and does not attend to sensory stimuli in contralateral hemispace or on contralateral hemibody (hemispatial neglect syndrome) • Pontine lesion: patient has ipsilateral hemiparesis and there is no neglect • Distinguish from partial seizure, in which head and eyes are deviated contralateral to seizure focus, but this is usually an intermittent phenomenon

Clinical Findings


• Frontoparietal lesion: • eyes deviated to side of lesion • no volitional gaze to side opposite lesion • doll’s head maneuver (and caloric ear irrigation) elicits horizontal gaze to side opposite lesion • contralateral hemiparesis and hemispatial neglect • patient initiates almost no activity, including speech, and appears passive (low tonic arousal state) • Pontine lesion: • eyes deviated to side opposite lesion • doll’s head maneuver fails to elicit horizontal gaze to side of lesion • may have hypertropia (skew deviation) • may have internuclear ophthalmoplegia (one and a half syndrome) and exotropia (pontine exotropia) • Focal seizure: • eyes deviated to side opposite seizure focus • jerk nystagmus to side of gaze is common • doll’s head maneuver usually fails to elicit eye movement toward side of seizure focus • often accompanied to clonic movements of limbs, face ipsilateral to gaze deviation • consciousness may be impaired • manifestations usually do not last beyond several minutes

Ancillary Testing • Parietal or pontine lesion: brain imaging shows lesion • Focal seizure: electroencephalography confirms diagnosis

Treatment • Parietal or pontine lesion: supportive care • Focal seizure: antiepileptics, treat underlying cause

Prognosis • Parietal lesion: • within days, volitional horizontal gaze to side opposite lesion begins to return but eyes remain deviated (gaze preference) • within weeks, eyes return to midposition and full volitional gaze is possible • Pontine lesion: • gaze deviation usually resolves but gaze abnormalities, skew deviation often persist • Focal seizure: • elimination of the epileptic discharge with medication stops manifestations

160

Fig. 9.4 Right horizontal gaze deviation. Eyes are deviated to the right in all positions of gaze.

B

Fig. 9.5 Right parietal contusion. Postcontrast (A) coronal and (B) axial T1 MRIs show a low signal area (arrows) in the right parietal region from closed head injury. The patient’s eyes were deviated to the right. With encouragement, the patient could gaze to the left (gaze preference).

Acute Horizontal Gaze Deviation

A

161

Spasm of the Near Reflex Key Facts • • • •

Triad of esotropia, miosis, and excessive accommodation (synkinetic near triad) Usually episodic but may be sustained Usually triggered by anxiety or malingering Patients complain of diplopia and blurred vision for distant objects and often headache • Diagnosis based on finding at least two components of the triad and no other pertinent abnormalities • Treatment options: • monocular occlusion • cycloplegia • psychotherapy • Avoid strabismus surgery because of high chance of secondary exotropia

Clinical Findings


• Diplopia and blurred vision for distant objects and often headache • Comitant, usually fluctuating, esotropia with reduced abduction • Eyes may be aligned with near fixation • Fluctuating pupil size and accommodation • Manifestations usually intermittent

Ancillary Testing • Not necessary

Differential Diagnosis • Acute convergence syndrome (see Acute convergence syndrome [acute comitant esotropia]) • Sixth cranial nerve palsy • Thalamic infarct, hemorrhage, tumor (thalamic esotropia, pseudoabducens palsy)

Treatment • Monocular occlusion, cycloplegia may break spasm • Psychosocial counseling may interrupt impulse to converge • Avoid eye muscle surgery (medial rectus recessions) because of high chance of causing secondary exotropia

Prognosis • Treatments often ineffective but problem is usually self-limited

162

Fig. 9.6 Spasm of the near reflex. In all positions of gaze, the eyes are convergently misaligned. In addition, the pupils are abnormally small (miosis).

Spasm of the Near Reflex 163

Ping Pong Gaze Key Facts • Arrhythmic slow conjugate horizontal movement of the eyes from one side to the other in a comatose patient • Caused by severe ischemic or metabolic insult to both cerebral hemispheres • Damaged cerebral hemispheres cannot control pontine gaze generators, which discharge automatically to move eyes back and forth • Often mistaken for epileptic nystagmus

Clinical Findings • Conjugate horizontal eye movements taking about 5 s to complete full cycle • Patient typically unresponsive except to painful tactile stimuli

Ancillary Testing

SECTION 9 • Cerebral Gaze Disorders 164

• CT or MRI may show extensive damage to both cerebral hemispheres • Normal MRI suggests metabolic or toxic damage, which may be shown with blood and urine tests

Differential Diagnosis • Epileptic nystagmus

Treatment • Directed at underlying disorder

Prognosis • Irreversible if ischemic damage • May be reversible if metabolic damage

Fig. 9.7 Ping pong gaze. The eyes drift conjugately from one side to another. There are no volitional eye movements because the patient is in coma.

Ping Pong Gaze

Fig. 9.8 Hypoxic–ischemic encephalopathy from strangulation. Diffusion-weighted MRI shows high signal involving the cerebral cortex and basal gray matter.

165

Section 10 Nystagmus Physiologic Nystagmus

168

Congenital Motor Nystagmus

170

Congenital Sensory Nystagmus

172

Monocular Pendular Nystagmus of Childhood

174

Spasmus Nutans

176

Peripheral Vestibular Nystagmus

178

Acquired Binocular Pendular Nystagmus

180

Sidebeat, Upbeat, and Downbeat Nystagmus

182

Epileptic Nystagmus

186

“Nystagmus” Of Extraocular Muscle Dysfunction

188

Convergence–retraction “Nystagmus”

190

Voluntary “Nystagmus”

192

Physiologic Nystagmus Key Facts • Horizontal or horizontal–torsional jerk nystagmus at extremes of horizontal gaze to both sides that is considered a variant of normal function • Often confused with pathologic nystagmus but usually distinguishable by noting clinical findings


Fast phase in direction of gaze Nystagmus amplitude is low and equal in amplitude in both directions of gaze Nystagmus amplitude may be greater in abducting than in adducting eye Nystagmus stops after four or fewer beats (unsustained) No oscillopsia during the nystagmus No nystagmogenic medications or drugs No other pertinent abnormalities on examination

Ancillary Testing

SECTION 10 • Nystagmus

• All tests normal (but not necessary)

Differential Diagnosis • Congenital nystagmus • Sidebeat nystagmus

Treatment • None

Prognosis • Nystagmus may appear on some examinations and not on others

168

Fig. 10.1 Physiologic nystagmus. In extremes of horizontal gaze, there is a lowamplitude jerk nystagmus with the fast component in the direction of gaze.

Physiologic Nystagmus 169

Congenital Motor Nystagmus Key Facts • • • •

Appears within first 6 months of life Unknown cause Isolated finding or associated with strabismus or developmental delay Diagnosis based on noting features of nystagmus, its early onset, and lack of any contributory neurologic findings • May be difficult to exclude congenital sensory nystagmus (see Congenital sensory nystagmus)

Clinical Findings


• Horizontal pendular nystagmus in primary position converting to jerk nystagmus on sidegaze • Remains in same plane in all fields of gaze (uniplanar) • Nystagmus often disappears or its amplitude markedly diminishes in eccentric gaze position (eccentric null zone) • Patient often adopts face turn to get eyes into null zone • Covering one eye often exacerbates jerk nystagmus in the open eye (latent nystagmus) • Patient does not report oscillopsia (but usually does report blurred vision) • Head nodding may be present • Visual acuity ranges from 20/40 to 20/200 for distance viewing • May be better for reading and in eccentric face turn position • No structural abnormalities on ophthalmologic or neurologic examination • In a rare variant, primary position right-beating nystagmus gives rise to primary position left-beating nystagmus in fixed cycles (periodic alternating nystagmus)

Ancillary Testing • Electroretinography is normal but may be necessary to rule out Leber congenital amaurosis • MRI is normal


Congenital sensory nystagmus Sidebeat, upbeat, or downbeat nystagmus Acquired binocular pendular nystagmus Spasmus nutans Square wave jerks Ocular flutter or opsoclonus Ocular dysmetria

Treatment • If there is a face turn, perform extraocular muscle surgery (Kestenbaum procedure) to shift null zone to primary position, particularly if visual acuity is better in eccentric face turn position • Do not inject botulinum toxin into extraocular muscles or retrobulbar space—it is ineffective and causes intolerable side effects • Avoid large extraocular muscle recessions, which have not been successful

Prognosis 170

• Lifelong condition in which visual acuity may always be subnormal but stable • Eye muscle surgery may be successful in eliminating face turn

Congenital Motor Nystagmus

Fig. 10.2 Congenital motor nystagmus. In primary position, there is a lowamplitude right-beating nystagmus that increases in amplitude on right gaze. In left gaze, there is a left-beating nystagmus. In upgaze and downgaze, the nystagmus remains in the horizontal plane (uniplanar).

171

Congenital Sensory Nystagmus Key Facts • Appears within first 6 months of life • Eye movements look like those of congenital motor nystagmus • Common causes: • Leber congenital amaurosis • achromatopsia • aniridia • albinism • optic neuropathy

Clinical Findings


• Eye movements identical to those of congenital motor nystagmus (see Congenital motor nystagmus) • Eyes may appear otherwise normal (Leber congenital amaurosis, achromatopsia, intracranial tumor) • Narrowed retinal arterioles (Leber congenital amaurosis), hypoplastic iris (aniridia), iris transillumination defects (albinism), small optic nerve (optic nerve hypoplasia, craniopharyngioma) • Visual acuity ranges from near normal to finger counting

Ancillary Testing • Electroretinography may show reduced amplitude in Leber congenital amaurosis • MRI may show atrophic optic nerves, cerebral malformations or tumors


Congenital motor nystagmus Sidebeat, upbeat, or downbeat nystagmus Acquired binocular pendular nystagmus Spasmus nutans Square wave jerks Ocular flutter or opsoclonus Ocular dysmetria

Treatment • None except for anterior visual pathway tumor


172

Fig. 10.3 Congenital sensory nystagmus. The nystagmus has features identical to that of congenital motor nystagmus, but the patient has an identifiable abnormality of the retina or optic nerves that impairs vision.

Congenital Sensory Nystagmus

Fig. 10.4 Retinal achromatopsia. Optic discs are slightly pale and foveal reflex is absent in a completely colorblind and visually impaired child with congenital sensory nystagmus.

173

Monocular Pendular Nystagmus of Childhood Key Facts • Monocular pendular nystagmus, usually vertical, present in childhood • Subnormal vision in oscillating eye • Common causes: • anterior visual pathway tumor (glioma, craniopharyngioma) • optic nerve hypoplasia • amblyopia • MRI to rule out anterior visual pathway tumor unless there is a predisposing cause for amblyopia and pupil reactions are normal

Clinical Findings


• Monocular pendular nystagmus, more commonly vertical • Subnormal visual acuity in oscillating eye • Anisometropia, strabismus, and media opacity may be causes of amblyopia in oscillating eye • Afferent pupil defect and pale and/or small optic disc are signs of optic neuropathy in oscillating eye

Ancillary Testing • MRI may show anterior visual pathway tumor

Differential Diagnosis • Spasmus nutans • Congenital motor or sensory nystagmus • Acquired binocular pendular nystagmus

Treatment • Monocular occlusion for amblyopia • Chemotherapy, radiotherapy, surgery, or observation for anterior visual pathway tumor

Prognosis • Depends on underlying lesion • Nystagmus may resolve if vision improves

174

Fig. 10.5 Monocular pendular nystagmus of childhood. In all positions of gaze, the right eye displays a vertical pendular nystagmus.

Monocular Pendular Nystagmus of Childhood

Fig. 10.6 Glioma of optic nerve and chiasm. Axial FLAIR MRI shows high signal mass in the optic chiasm and left optic nerve (arrow). The patient displayed monocular pendular nystagmus in the left eye.

175

Spasmus Nutans Key Facts • Idiopathic triad of low-amplitude binocular pendular nystagmus, torticollis, and head nodding • Torticollis and nodding often absent • Appears with first 3 years of life, usually within first year • Disappears spontaneously within 36 months, leaving no after-effects • Cannot be distinguished easily from congenital nystagmus, monocular pendular nystagmus of childhood, or ocular flutter or opsoclonus

Clinical Findings • Low-amplitude binocular pendular (shimmery) nystagmus, sometimes accompanied by torticollis and/or head nodding • Nystagmus amplitude may be so low in one eye that it escapes notice • Ophthalmologic and neurologic examinations otherwise normal • No systemic abnormalities


Ancillary Testing • Evaluate for: • retinal photoreceptor dystrophies (electroretinogram) • anterior visual pathway tumors (brain MRI) • meningoencephalitis (brain MRI, lumbar puncture, electroencephalogram) • occult neuroblastoma (chest and abdomen MRI, nuclear scan, urine catecholamines)

Differential Diagnosis • Congenital motor or sensory nystagmus • Monocular pendular nystagmus of childhood • Ocular flutter or opsoclonus

Treatment • None

Prognosis • All findings disappear completely within 36 months and leave no after-effects

176

Fig. 10.7 Spasmus nutans. In all positions of gaze, the eyes display a lowamplitude horizontal (shimmery) pendular nystagmus. The nystagmus amplitude in one eye is often so low that the nystagmus appears to be monocular.

Spasmus Nutans 177

Peripheral Vestibular Nystagmus Key Facts • Unidirectional horizontal–torsional jerk nystagmus with fast phase directed away from side of vestibular lesion • Nystagmus resolves within days (brainstem compensation) • Common causes: • viral labyrinthitis • viral neuronitis • benign paroxysmal positional vertigo (BPPV) • Ménière disease • otic trauma • middle or inner ear infections, tumors, or stroke • autoimmune conditions • perilymphatic fistula

Clinical Findings


• Nystagmus fast phase is always directed to same side regardless of gaze position, unlike sidebeat nystagmus, in which the fast phase is directed to the side of gaze (direction-changing) • Nystagmus amplitude increased by ocular occlusion or strong plus (Frenzel) lenses (unlike sidebeat nystagmus) • Saccades, pursuit are normal (unlike sidebeat nystagmus) • Patient often complains of nausea, vomiting, vertigo, hearing loss and/or tinnitus and falls to the side of the lesion • Patient often has severe imbalance but no extremity or speech ataxia • Manifestations induced or exacerbated by rapid shifts in head position

Ancillary Testing • Otologic, audiologic, and vestibular testing (including videonystagmography) helps confirm diagnosis • Brain imaging, which is usually not necessary if diagnostic criteria are met, will be normal unless there are structural abnormalities in middle or inner ear

Differential Diagnosis • Sidebeat nystagmus

Treatment • Oral antihistamine and antiemetic are helpful palliatives for vertigo and nausea • Direct other treatment at underlying lesion • In BPPV, otoconial repositioning maneuvers may be indicated

Prognosis • Nystagmus resolves within days • In BPPV, otoconial repositioning maneuvers may be curative • Other symptoms of viral labyrinthitis and neuronitis resolve spontaneously within weeks

178

Fig. 10.8 Peripheral vestibular nystagmus. The eyes display a counterclockwise horizontal rotary jerk nystagmus in all positions of gaze. In this case, the lesion is in the right labyrinth or vestibular nerve.

Peripheral Vestibular Nystagmus 179

Acquired Binocular Pendular Nystagmus Key Facts • Acquired horizontal, vertical, torsional, elliptic, or circular pendular nystagmus • Causes: • multiple sclerosis • other brainstem lesions • congenital midline dysgenesis • Whipple disease

Clinical Findings


• Horizontal, vertical, torsional, elliptic, or circular pendular nystagmus • Patient usually complains of oscillopsia (smeary vision or illusion of fine movement of viewed objects) • One eye may rise while the other falls (seesaw nystagmus) • Eyes may move in synchrony with oscillations of palate, platysma, pharynx, larynx, or diaphragm (oculopalatal myoclonus) • Eyes may converge synchronously with masticator muscle spasms (oculomasticatory myorhythmia)

Ancillary Testing • MRI often shows pertinent lesions of brainstem • Oculopalatal myoclonus: enlargement of inferior olive in medulla is sometimes visible on T2 sequences as a late finding • Seesaw nystagmus: lesion is often in the diencephalic or midbrain region • Oculomasticatory myorhythmia: serum and cerebrospinal fluid PCR is positive for Tropheryma whippelii DNA and small intestine biopsy shows characteristic pathology


Congenital nystagmus Monocular pendular nystagmus of childhood Ocular flutter or opsoclonus Psychogenically induced eye movements

Treatment • Medications that may help: Seesaw nystagmus: baclofen, clonazepam Oculopalatal myoclonus: clonazepam, scolopamine, valproic acid, gabapentin, or trihexyphenidyl • But these medications only rarely reduce oscillopsia or improve vision and may exacerbate other neurologic manifestations • Intramuscular and retrobulbar botulinum toxin injections do not reduce oscillopsia or improve vision • Large extraocular muscle recessions do not reduce oscillopsia or improve vision


180

Fig. 10.9 Acquired binocular pendular nystagmus. Both eyes display a pendular nystagmus with an oval trajectory. The eyes look like egg beaters.

Acquired Binocular Pendular Nystagmus

Fig. 10.10 Sagittal FLAIR MRI shows multiple high signal areas in the cerebrum and cerebellum, typical of multiple sclerosis.

181

Sidebeat, Upbeat, and Downbeat Nystagmus Key Facts • Horizontal or vertical jerk nystagmus that reflects brainstem vestibulocerebellar dysfunction • May be caused by congenital malformations or acquired structural or metabolic abnormalities, toxins, or medications • Common acquired causes: • tumors • demyelination • infections • neurodegenerative disorders • metabolic disturbances (hypomagnesemia, thiamine or cyanocobalamin deficiency) • medication toxicity (phenytoin, lithium, carbamazepine) • Medical treatment rarely effective in relieving oscillopsia


Clinical Findings • Horizontal or vertical jerk nystagmus • Occlusion or Frenzel lenses do not affect nystagmus amplitude • Sidebeat nystagmus: usually first appears on sidegaze and beats in direction of gaze • Upbeat nystagmus: may be present in primary position and increases in amplitude in upgaze • Downbeat nystagmus: may be present in primary position and increases in amplitude on down-and-sidegaze • Periodic alternating nystagmus (PAN): • beats to one side in primary position with increasing and then decreasing amplitude for about 90 s • eyes are stationary for about 10 s • the nystagmus begins in the opposite direction with increasing and then decreasing amplitude as before • each full cycle lasts nearly 3 min • Ataxia, skew deviation, alteration in consciousness may be present

Ancillary Testing • Brain MRI (concentrating on brainstem, cerebellum, and cervical cord) often shows structural abnormalities but often normal in toxic, metabolic, or degenerative conditions • Full neurologic evaluation recommended


182

Congenital nystagmus Peripheral vestibular jerk nystagmus Ocular flutter or opsoclonus Ocular dysmetria

Fig. 10.11 Sidebeat nystagmus. The eyes display no nystagmus in the primary position. In right gaze, there is a right-beating (jerk) nystagmus. In left gaze, there is a left-beating (jerk) nystagmus.

Sidebeat, Upbeat, and Downbeat Nystagmus

Fig. 10.12 Upbeat nystagmus. The eyes display an upbeat nystagmus in all positions of gaze.

183

Sidebeat, Upbeat, and Downbeat Nystagmus (Continued) Treatment • Directed at underlying cause • Surgical treatment, including Chiari malformation repair, does not reliably relieve nystagmus • Medical treatment, indicated if oscillopsia is disabling, is disappointing and may exacerbate other neurologic manifestations • Some physicians report oscillopsia reduction in PAN with baclofen, in downbeat with clonazepam, baclofen, scopolamine, and gabapentin • Intramuscular or retrobulbar botulinum toxin injection does not reduce oscillopsia • Large extraocular muscle recessions do not reduce oscillopsia

Prognosis • Depends on underlying cause

SECTION 10 • Nystagmus 184

Fig. 10.13 Downbeat nystagmus. The eyes display a jerk nystagmus with a fast downward component. The nystagmus is often most obvious when the eyes are in downgaze.

Sidebeat, Upbeat, and Downbeat Nystagmus (continued)

Fig. 10.14 Chiari malformation in a patient with downbeat nystagmus. Precontrast sagittal T1 MRI shows that the cerebellar tonsil has descended into the foramen magnum (arrow). The low signal in the center of the cervical spinal cord (arrowhead) is a syrinx, a common accompaniment of Chiari malformation.

185

Epileptic Nystagmus Key Facts • Horizontal jerk nystagmus during seizure • Horizontal gaze and head deviation to side contralateral to seizure focus • Usually accompanied by tonic–clonic movements of face and extremities on side of gaze deviation • Usually resolves within minutes but may be sustained (partial status epilepticus) • When seizure ends, eyes may deviate to opposite side but nystagmus stops

Clinical Findings • Fast, moderate amplitude horizontal jerk nystagmus in direction of gaze • Eyes deviated in direction of fast phase • Face and extremities often twitching or contracted on side contralateral to seizure focus

Ancillary Testing


• If electroencephalogram is being recorded, epileptic discharges will be captured • Interictal electroencephalogram may also be abnormal • MRI often shows lesion at seizure focus

Differential Diagnosis • Nothing else causes this combination of findings!

Treatment • Directed at underlying lesion • Anticonvulsants

Prognosis • Depends on ability to control seizures

186

Fig. 10.15 Epileptic nystagmus. The eyes are deviated to the right and display a jerk nystagmus with a fast component to the right.

Epileptic Nystagmus

Fig. 10.16 Occipital arteriovenous malformation causing epileptic nystagmus. Axial T2 MRI shows a mass of inhomogeneous signal in the left parieto-occipital region (arrow) that proved to be an arteriovenous malformation.

187

“Nystagmus” of Extraocular Muscle Dysfunction Key Facts • Jerk nystagmus in direction of gaze in presence of impaired extraocular muscle function (cranial neuropathy, neuromuscular transmission failure, extraocular myopathy) • Occurs in field of action of weak or restricted extraocular muscle • Usually low amplitude, unsustained, and appears only in extreme gaze • May be confused with myasthenia gravis or internuclear ophthalmoplegia

Clinical Findings • Low-amplitude, unsustained jerk nystagmus in field of action of dysfunctional extraocular muscle • Usually other evidence of cranial neuropathy, neuromuscular transmission failure, or extraocular myopathy, but may be subtle


Ancillary Testing • Tests for myasthenia gravis may be positive • Brain or orbit imaging may be abnormal

Differential Diagnosis • Myasthenia gravis • Internuclear ophthalmoplegia

Treatment • Depends on condition

Prognosis • Depends on condition

188

“Nystagmus” of Extraocular Muscle Dysfunction

Fig. 10.17 Nystagmus of extraocular muscle weakness. The right eye has reduced adduction from medial rectus malfunction and displays a few beats of left-beating (jerk) nystagmus in left gaze. Any disorder of ocular motor nerves, myoneural junction, or extraocular muscle can produce mild oscillation of the eye when it is brought into the appropriate field of action.

189

Convergence–retraction “Nystagmus” Key Facts • Repetitive convergence and retraction saccades of both eyes provoked by attempted upgaze or by viewing an optokinetic strip moved downward • Not a true nystagmus (because nystagmus is never initiated by a saccade) • Co-contraction of all extraocular muscles produces repetitive saccades • Always associated with impaired upgaze • Caused by a lesion of the dorsal midbrain region (see Dorsal midbrain [pretectal] syndrome)

Clinical Findings • Repetitive convergence and retraction saccades of both eyes provoked by attempted upgaze or by viewing an optokinetic strip moved downward • Impaired upgaze and other signs of dorsal midbrain dysfunction • Patient experiences brow ache whenever convergence–retraction “nystagmus” is provoked


Ancillary Testing • MRI usually discloses an abnormality of the dorsal midbrain region

Differential Diagnosis • Nothing else looks like this



190

A

B

Fig. 10.19 Pineal germinoma causing convergence–retraction “nystagmus”. Postcontrast (A) sagittal and (B) axial T1 MRIs show enhancing (high signal) mass (arrows) in the pineal region that infiltrates the tectal plate.

Convergence–retraction “Nystagmus”

Fig. 10.18 Convergence–retraction “nystagmus”. On attempted upgaze, the eyes do not move upward very much. Instead, they converge and retract a few times. This reaction looks like clonus elicited at the ankles when the Achilles deep tendon reflex is tested in a patient with an upper motor neuron lesion.

191

Voluntary “Nystagmus” Key Facts • • • • •

Voluntary bursts of back to back saccades in horizontal plane Not a true nystagmus (because nystagmus is never initiated by a saccade) Episodes are brief and tiring to the patient May be used to simulate illness Mistaken for ocular flutter or opsoclonus but distinguished by lack of accompanying neurologic findings (tremor, titubation, myoclonus, ataxia)

Clinical Findings • Bursts of quick, quivery oscillations in both eyes, usually initiated by convergence • No other ophthalmic or neurologic findings

Ancillary Testing • None needed



Congenital nystagmus Peripheral vestibular nystagmus Sidebeat nystagmus Ocular flutter or opsoclonus Habit spasms (tics)

Treatment • Explanation to patient of the voluntary nature of this phenomenon and/or reassurance

Prognosis • May be used repeatedly to simulate illness

192

Fig. 10.20 Voluntary “nystagmus”. The patient is somehow able to initiate a series of to and fro horizontal saccades. Each episode lasts only a few seconds. The eye movement abnormality is identical to ocular flutter except that it is psychogenic.

Voluntary “Nystagmus” 193

Section 11 Saccadic Disorders Superior Oblique Myokymia

196

Square Wave Jerks

198

Ocular Flutter and Opsoclonus

200

Ocular Dysmetria

202

Ocular Bobbing

204

Superior Oblique Myokymia Key Facts • Repetitive monocular downward intorsional saccades and a sensation of twitching or trembling of the affected eye, blurred or double vision, or oscillopsia • Caused by involuntary contractions of ipsilateral superior oblique muscle • Episodes occur in flurries in otherwise healthy adults • Attributed to abnormal excitability of trochlear nerve or instability of trochlear muscle membrane

Clinical Findings • Small repetitive intorsional movements of symptomatic eye • All other aspects of ophthalmic and neurologic examinations are normal

Ancillary Testing • Not necessary if findings are classic

SECTION 11 • Saccadic Disorders 196

Differential Diagnosis • If strictly monocular, no other condition need be considered • If binocular, consider acquired binocular pendular nystagmus (see Acquired binocular pendular nystagmus)

Treatment • Gabapentin, carbamazepine, baclofen, or propranolol may be effective, but spontaneous remissions are so frequent that medication efficacy not rigorously proven • Recession of anterior portion of superior oblique muscle may be successful in rare medically refractory cases with disabling symptoms

Prognosis • Often remits spontaneously for long periods or permanently

Fig. 11.1 Superior oblique myokymia. The affected eye (right eye here) displays fine rotary oscillations that differ from nystagmus in being initiated by saccades and being arrhythmic. The oscillations are episodic and always monocular!

Superior Oblique Myokymia 197

Square Wave Jerks Key Facts • Horizontal back and forth saccades that interrupt fixation • May be normal variant if small (<5º) and infrequent (<10/min) but otherwise a non-specific sign of brainstem dysfunction • Produces no symptoms • Common causes: • progressive supranuclear palsy • cerebellar degeneration • brainstem trauma • multiple sclerosis • schizophrenia • Parkinson disease • Huntington disease

Clinical Findings

SECTION 11 • Saccadic Disorders

• Horizontal back and forth saccades that interrupt fixation • Pathologic if amplitude >5º or frequency >10/min • Often accompanied by: • saccadic pursuit • hypometric saccades • other neurologic abnormalities

Ancillary Testing • Choice of tests depends on clinical findings


Congenital nystagmus Ocular dysmetria Ocular flutter Voluntary “nystagmus” Poor attention



198

Fig. 11.2 Square wave jerks. Low-amplitude saccades interrupt fixation and take the eyes off target to one side, where they are briefly still and then return with another saccade to the fixation point. Often mistaken for nystagmus, this eye movement abnormality is actually a saccadic intrusion on fixation. It is a nonspecific sign of brainstem dysfunction.

Square Wave Jerks 199

Ocular Flutter and Opsoclonus Key Facts


• Bursts of involuntary back to back binocular conjugate saccades that take eyes away from primary position • In ocular flutter, the trajectory is strictly in the horizontal plane; in opsoclonus it may be in any plane • Caused by dysfunction of pontine pause cells that normally prevent involuntary conjugate eye movements • Common causes in children: • postviral autoimmune disorder • paraneoplastic disorder associated with metastatic neuroblastoma • Common causes in adults: • postviral or paraneoplastic encephalitic manifestation of metastatic lung, breast, or ovarian cancer • Uncommon causes: • drug toxicity (lithium, amitriptyline, cocaine, phenytoin) or poisoning (toluene, thallium, chlordecone, organophosphates, strychnine) • hyperosmolar coma • brainstem hemorrhage • multiple sclerosis • Treatment of underlying cancer may improve neurologic manifestations • Adrenocorticotropic hormone (ACTH), corticosteroid, plasmapheresis, or immunoglobulin treatment may improve on natural course of paraneoplastic and postviral encephalitis

Clinical Findings • Bursts of involuntary back to back binocular conjugate saccades that take eyes away from primary position • In ocular flutter, the trajectory is strictly in horizontal plane; in opsoclonus it may be in any plane • Associated with: • brief muscle contractions (myoclonus) at joints • head and trunk oscillations (titubation) • extremity tremor • ataxia

Ancillary Testing • Brain imaging usually negative • Lumbar puncture may disclose mild pleocytosis or protein elevation • In children with metastatic neuroblastoma, the following may be positive: • urine catecholamines • chest, abdomen, and pelvis imaging • MIBG nuclear medicine scan • In adults, primary cancer may become apparent with structural (MRI) or metabolic (PET) scanning

Differential Diagnosis • Ocular dysmetria • Voluntary nystagmus • Square wave jerks

Treatment • Treatment of underlying cancer may improve neurologic manifestations • ACTH, corticosteroid, plasmapheresis, or immunoglobulin treatment for paraneoplastic and postinfectious encephalitis

Prognosis • Postviral autoimmune disorder: eye findings resolve within months, but ataxia and cognitive dysfunction may persist • Adult paraneoplastic disorder: findings usually do not resolve and survival time is short • Neuroblastoma with ocular flutter or opsoclonus has better prognosis than neuroblastoma without ocular flutter or opsoclonus 200

Fig. 11.3 Ocular flutter. Involuntary rapid saccades move the eyes conjugately off target. As the movements are limited to the horizontal plane, this is called ocular flutter.

Ocular Flutter and Opsoclonus

Fig. 11.4 Opsoclonus. The conjugate saccadic eye movements occur in horizontal and vertical planes.

201

Ocular Dysmetria Key Facts • Refixational eye movements lead to conjugate saccadic ocular oscillations • Usually accompanied by extremity, gait, or speech ataxia • Reflects cerebellar system dysfunction

Clinical Findings • When eyes make a refixational movement, they oscillate before settling on the target • Usually accompanied by ataxia • Eye movements do not cause visual symptoms

Ancillary Testing • Brain imaging may show lesions of brainstem or cerebellum


SECTION 11 • Saccadic Disorders 202

• Voluntary nystagmus • Congenital nystagmus • Ocular flutter or opsoclonus



Fig. 11.5 In making a saccade toward a new target, the eyes overshoot, oscillate, and finally settle on it.

Ocular Dysmetria

Fig. 11.6 Cerebellar hemorrhage. Axial CT shows high signal attenuation in the right cerebellar hemisphere, reflecting acute bleeding (arrow).

203

Ocular Bobbing Key Facts • Vertical conjugate oscillation of eyes in a comatose patient • May represent disinhibition of automatic midbrain vertical eye movement centers • Common causes: • pontine hemorrhage or infarct • metabolic or anoxic encephalopathy

Clinical Findings


• Typical ocular bobbing: • fast downward movement followed by slow upward drift to primary position • horizontal eye movements absent • Ocular dipping: • slow downward movement followed by fast upward movement • horizontal eye movements often intact • Reverse bobbing: • fast upward movement followed by slow downward drift to primary position • horizontal eye movements often intact • Reverse dipping: • a slow upward drift followed by a fast downward movement • horizontal eye movements often intact

Ancillary Testing • In bobbing, brain imaging often shows intrinsic brainstem lesion • If brain imaging is negative, consider metabolic or toxic conditions

Differential Diagnosis • Acquired binocular pendular nystagmus • Epileptic nystagmus • Upbeat or downbeat nystagmus



204

Fig. 11.7 Ocular bobbing. The eyes involuntarily move downward rapidly (solid lines) and drift slowly up to primary position (dotted lines).

Ocular Bobbing

Fig. 11.8 Axial precontrast CT shows acute hypertensive pontine hemorrhage (arrow) that produced coma and ocular bobbing.

205

Section 12 Pupil Disorders Tonic Pupil

208

Argyll Robertson Pupils

210

Tectal (Dorsal Midbrain) Pupils

212

Pharmacologically Dilated Pupil

214

Mydriatic Pupil of Third Cranial Nerve Palsy

216

Mydriatic Pupil of Traumatic Iridoplegia

218

Episodic Pupil Dilation

220

Physiologic (Simple, Benign, Essential) Anisocoria

222

Horner Syndrome

224

Tonic Pupil Key Facts • Affected pupil constricts segmentally and more to a near target than to direct light (light–near dissociation) • Affected pupil redilates slowly on changing fixation from a near to a distant target (tonicity) • Affected pupil constricts following instillation of <1/8% pilocarpine (parasympathetic denervation supersensitivity) • Common causes: • presumed viral or postviral dysautonomia affecting ciliary ganglion or ciliary nerves (Adie tonic pupil) • sometimes also dorsal root ganglia are damaged causing impaired deep tendon reflexes (Holmes–Adie syndrome) • Uncommon causes: • retinal laser photocoagulation • orbital tumors, surgery, or trauma • widespread neuropathies, including Guillain–Barré syndrome, Riley–Day syndrome, hereditary neuropathies, amyloidosis, syphilis, pandysautonomias • No treatment except sometimes bifocals (see below)

SECTION 12 • Pupil Disorders

Clinical Findings • Anisocoria with affected pupil larger or smaller than fellow pupil in dim light • Affected pupil constricts minimally to direct light within days of onset • ≥8 weeks after onset, affected pupil does not constrict normally to direct light but constricts slowly on viewing a target at reading distance (tonic light–near dissociation) • May have temporary loss of accommodation • Slit-lamp examination shows segmental immobility of iris sphincter (segmental palsy) and subtle transillumination defects (iris atrophy) • Deep tendon reflexes may be absent (Holmes–Adie syndrome) • Corneal sensation in affected eye may be reduced, but there are no other pertinent ophthalmic findings • Sometimes evidence of retinal photocoagulation or orbital tumor, trauma, or surgery

Ancillary Testing • Affected pupil constricts to dilute (<1/8%) pilocarpine • Neurologic or autonomic testing may show evidence of widespread neuropathy • Serologic test for syphilis may be positive

Differential Diagnosis • Pharmacologically dilated pupil • Third cranial nerve palsy • Iris atrophy from trauma, intraocular surgery, inflammation, congenital anomaly • Botulism

Treatment • Patients with deficient or tonic accommodation may benefit from bifocals • Patients with widely dilated pupil may benefit from periodic instillation of dilute pilocarpine

Prognosis • Accommodation recovers fully within weeks • Affected pupil becomes smaller within months but never regains normal constriction to light • If only one pupil is affected at presentation, the other pupil may become affected within months to years • Patients rarely have lingering ophthalmic symptoms

208

A

B

Tonic Pupil

C

D

Fig. 12.1 Tonic right pupil. (A) In darkness, the right pupil is dilated. (B) In brightness, the right pupil does not constrict but the left pupil constricts normally. (C) When a target is viewed at reading distance, both pupils constrict, although right pupil constricts slowly (tonic near response) and segmentally. (D) After instillation of 1/10% pilocarpine in each eye, the right pupil constricts (cholinergic denervation supersensitivity) but the left pupil does not.

209

Argyll Robertson Pupils Key Facts • Unilateral or bilateral miosis and usually anisocoria • Affected pupil fails to constrict to light but does constrict to a near target (light–near dissociation) • Affected pupils lack tonic features, segmental palsy, or denervation supersensitivity • Associated with positive syphilis serology and other neurologic manifestations of syphilis, especially tabes dorsalis • Location of responsible lesion is unknown

Clinical Findings


• Unilateral or bilateral miosis and usually anisocoria • Affected pupil fails to constrict to light but does constrict to a near target (light–near dissociation) • Affected pupils lack tonic features, segmental palsy, or denervation supersensitivity • Neurologic manifestations of syphilis may be present

Ancillary Testing • Positive syphilis serology in serum or spinal fluid in some cases

Differential Diagnosis • Miosis caused by instillation of pharmacologic agent • Tonic pupil • Iris damage from trauma, inflammation, ocular surgery or laser treatment, congenital anomaly • Denervated pupils in autonomic neuropathy


Prognosis • Pupil findings do not change • Patients are not symptomatic from pupil abnormality

210

A

B

D

Fig. 12.2 Bilateral Argyll Robertson pupils. (A) In darkness, both pupils are slightly small. (B) In brightness, neither pupil constricts. (C) When a target is viewed at reading distance, both pupils constrict normally. (D) After instillation of 1/10% pilocarpine in each eye, neither pupil constricts.

Argyll Robertson Pupils

C

211

Tectal (Dorsal Midbrain) Pupils Key Facts • Anisocoria may be present • Bilateral dilated pupils that do not constrict or constrict poorly to light but may constrict normally to a near target (tectal light–near dissociation) • Lesion affects dorsal (tectal) midbrain • If it extends ventrally into tegmental midbrain, pupils do not constrict to a near target • Pupil abnormality attributed to disconnection of tectal midbrain portion of afferent pupil reflex pathway from efferent parasympathetic (Edinger–Westphal) nuclei • Common causes: • hydrocephalus • pineal region or midbrain tectal tumor • demyelinization • infarction


Clinical Findings • Bilateral light–near dissociated mydriatic pupils • Other features of dorsal midbrain syndrome: • lid retraction • vertical gaze deficit • convergence–retraction “nystagmus” • hypertropia • torsional nystagmus

Ancillary Testing • MRI may show ventriculomegaly or signal abnormalities in pineal or midbrain tectal regions


Bilateral tonic pupils Iris atrophy from ocular surgery, trauma, ischemia, or congenital anomaly Botulism Denervated pupils in autonomic neuropathy



212

A

B

D

Fig. 12.3 Tectal (dorsal midbrain) pupils. (A) In dim illumination, both pupils are larger than normal, but unequally. (B) In bright light, neither pupil constricts. (C) When a target is viewed at reading distance, both pupils constrict normally. (D) After instillation of 1/10% pilocarpine in each eye, neither pupil constricts.

A

Tectal (Dorsal Midbrain) Pupils

C

B

Fig. 12.4 Tectal glioma. Postcontrast (A) sagittal and (B) axial T1 MRI shows enhancing cystic mass in tectal region (arrow).

213

Pharmacologically Dilated Pupil Key Facts • Unilateral or bilateral mydriatic pupils that do not constrict or constrict poorly to light • Caused by topical exposure to parasympatholytic or sympathomimetic agent • If parasympatholytic agent is responsible, there will be impaired accommodation in patients aged <45 years • Common causes: • eyedrops • scopolamine patch • glycopyrrolate cream for hyperhidrosis • atropinic vegetable substances • aerosols in ventilator regimens • Cannot be attributed to orally or parenterally administered medications with parasympatholytic properties • Always reversible if offending agent is removed


Clinical Findings • Unilateral or bilateral mydriatic pupils that do not constrict or constrict poorly to light • Parasympatholytic exposure: • impaired accommodation in patients aged <45 years • Sympathomimetic exposure: • eyelid may be retracted • conjunctiva may be blanched • pupil often constricts to bright light • accommodation is spared • Pupil may be slightly eccentric, but there is no slit-lamp evidence of segmental palsy, iris atrophy, or synechiae

Ancillary Testing • Parasympatholytic agent: affected pupil constricts less than fellow pupil to topical pilocarpine 1% • Sympathomimetic agent: both pupils will constrict normally to topical pilocarpine 1%

Differential Diagnosis • Recent onset tonic pupil that has not yet developed tonicity, light–near dissociation, or denervation supersensitivity • Iris dysplasia, inflammation, trauma (including intraocular surgery), prior ischemia from angle closure, carotid occlusive disease • Mydriatic pupil of third cranial nerve palsy

Treatment • Eliminate topical exposure to pharmacologic agents with sympathomimetic or parasympathomimetic properties

Prognosis • Pupil returns to normal as offending agent gradually metabolized

214

A

B

D

Pharmacologically Dilated Pupil

C

E

Fig. 12.5 Pharmacologically dilated right pupil. (A) In dim illumination, right pupil is much larger than left pupil. (B) In bright light, the right pupil does not constrict but the left pupil constricts normally. (C) When a target is viewed at reading distance, the right pupil does not constrict but the left constricts normally. (D) After instillation of 1/10% pilocarpine, neither pupil constricts. (E) After instillation of 1% pilocarpine, the right pupil does not constrict but the left pupil constricts.

215

Mydriatic Pupil of Third Cranial Nerve Palsy Key Facts • Mydriatic pupil with impaired constriction to light and near target • Always accompanied by other evidence of third cranial nerve palsy (ptosis or impaired adduction, infraduction, or supraduction; see Third cranial nerve palsy) • Diplopia usually present • Suggests compression of third cranial nerve by intracranial lesion such as berry aneurysm • Isolated mydriasis is never a manifestation of a third cranial nerve palsy

Clinical Findings • Mydriatic, poorly reactive pupil • Ipsilateral ptosis or adduction, infraduction, supraduction deficits • Diplopia usually present


SECTION 12 • Pupil Disorders 216

• Iris trauma • Pharmacologically dilated pupil

Ancillary Testing • Brain imaging (MRI or magnetic resonance angiography, CT or CT angiography) may show: • mass lesion • aneurysm • enhancement of third cranial nerve or meninges

Treatment • Depends on underlying condition • Prognosis • Depends on underlying condition

A

B

D

E

Fig. 12.6 (A) In darkness, the pupil is dilated in the right eye, which has ptosis and is exodeviated as part of a right third cranial nerve palsy. (B) In brightness, the right pupil does not constrict but the left pupil constricts normally. (C) When a target is viewed at reading distance, the right pupil does not constrict but the left constricts normally. (D) After instillation of 1/10% pilocarpine, neither pupil constricts. (E) After instillation of 1% pilocarpine, both pupils constrict.

Mydriatic Pupil of Third Cranial Nerve Palsy

C

217

Mydriatic Pupil of Traumatic Iridoplegia Key Facts • Mydriatic, usually oval or serrated pupil resulting from damage to iris sphincter and/or stroma • Affected pupil displays impaired constriction to light and to a near target • History of direct eye trauma, intraocular surgery, or anterior chamber inflammation usually present • Slit-lamp examination usually discloses iris abnormalities • Topical pharmacologic tests can be used to exclude other conditions

Clinical Findings • Mydriatic, oval, or serrated pupil • Sometimes iris sphincter tears, stromal atrophy, transillumination defects, synechiae • Sometimes evidence of anterior chamber angle recession



• • • •

Tonic pupil Mydriatic pupil of third cranial nerve palsy Pharmacologically dilated pupil Horner syndrome

Ancillary Testing • Topical instillation of 1/10% pilocarpine causes no constriction of affected pupil • Topical instillation of 1% pilocarpine may cause segmental constriction of affected pupil

Treatment • None

Prognosis • Condition likely to be stable

218

A

B

D

E

Fig. 12.7 (A) In darkness, the right pupil is dilated and oval because of segmental iris damage. (B) In brightness, the right pupil does not constrict but the left pupil constricts normally. (C) When a target is viewed at reading distance, the right pupil does not constrict but the left constricts normally. (D) After instillation of 1/10% pilocarpine, neither pupil constricts. (E) After instillation of 1% pilocarpine, the right pupil constricts segmentally and the left pupil constricts normally.

Mydriatic Pupil of Traumatic Iridoplegia

C

219

Episodic Pupil Dilation Key Facts • Temporary (<12 h) anisocoria without other neuro-ophthalmic signs • Patient may complain of blurred vision, difficulty focusing on near target, headache • Most common in young or middle-aged women • Considered a dysautonomic manifestation (parasympatholytic or sympathomimetic) often associated with migraine or seizure • Examination sometimes shows elongated pupil (tadpole pupil) • No need for work-up

Clinical Findings


• Anisocoria with normally reactive pupils or mydriatic pupil that constricts relatively poorly to light • Affected pupil may be elongated (tadpole pupil) • No other neuro-ophthalmic findings • May occur in conjunction with migraine-like headache or following a seizure

Ancillary Testing • Pupil pharmacologic testing not necessary if anisocoria has resolved • No need for neuroimaging in typical cases, even if no history of migraine or seizure

Differential Diagnosis • Resolving pharmacologically dilated pupil

Treatment • None

Prognosis • Episodes may recur

220

A

B

D

Episodic Pupil Dilation

C

E

F

Fig. 12.8 Episodic right pupil dilation. (A) In darkness, the right pupil is larger than the left. (B) In brightness, the right pupil does not constrict normally. (C) When a target is viewed at reading distance, the right pupil does not constrict normally. (D) Instillation of 1/10% pilocarpine fails to constrict either pupil. (E) Instillation of 1% pilocarpine constricts both pupils. (F) Twenty four hours later, the pupils are of equal size.

221

Physiologic (Simple, Benign, Essential) Anisocoria Key Facts • • • • • •

Anisocoria of <1 mm in dim illumination attributed to normal variation Mechanism unknown May be intermittent, and larger pupil may switch sides Both pupils constrict normally to light No iris pathology or exposure to topical autonomically active drugs No pharmacologic signs of iris dilator muscle denervation


Anisocoria of <1 mm in dim illumination Pupils constrict normally to light No pupil dilation lag when ambient light turned off No pharmacologic signs of iris dilator muscle denervation No other pertinent neuro-ophthalmic findings


Ancillary Testing • <1 mm anisocoria after instillation of cocaine 10% • No change in anisocoria after instillation of apraclonidine 0.5%

Differential Diagnosis • Horner syndrome • Occult iris pathology

Treatment • None

Prognosis • Anisocoria may be intermittent, and larger pupil may switch sides

222

A

B

Fig. 12.9 Physiologic anisocoria. (A) In darkness, right pupil is larger than left pupil. (B) In brightness, both pupils constrict normally. (C) After instillation of 10% cocaine, both pupils dilate normally.

Physiologic (Simple, Benign, Essential) Anisocoria

C

223

Horner Syndrome Key Facts


• Miosis and ipsilateral ptosis • Caused by sympathetic denervation • Lesion may lie within the first (central), second (preganglionic), or third (postganglionic) segment of oculosympathetic pathway • Causes of postganglionic Horner syndrome: • cervical carotid dissection • surgery, trauma, or mass in neck • cavernous sinus lesion • cluster headache • idiopathic • Causes of preganglionic Horner syndrome in children: • birth injury • neuroblastoma • Causes of preganglionic Horner syndrome in adults: • surgery, trauma, or mass in paraspinal, neck, or apical lung regions • Causes of central Horner syndrome: • dorsolateral medullary infarction (Wallenberg syndrome) • cervicothoracic cord syrinx, trauma, or tumor

Clinical Findings • • • • • • • •

Anisocoria in dim light with normal pupil constriction to bright light Ptosis ipsilateral to smaller pupil Anisocoria rarely >2 mm Dilation lag of affected pupil Ptosis, never >3 mm, need not be present Ipsilateral elevation of lower lid (upside down ptosis) sometimes Ipsilateral conjunctival injection sometimes Ipsilateral facial anhydrosis (central or preganglionic lesions)

Ancillary Testing • 30 min after instillation of cocaine 10%, residual anisocoria should be >1 mm • Apraclonidine 0.5% should eliminate anisocoria or cause reversal of anisocoria (small pupil becomes larger pupil) • MRI or magnetic resonance angiography should extend from skull vertex to midthoracic region regardless of results of topical pharmacologic pupil tests • use dedicated ‘carotid dissection’ protocol if Horner syndrome is acute

Differential Diagnosis • Ptosis from trauma, senescence, or myasthenia gravis • Miosis from physiologic anisocoria or iris pathology

224

A

B

Fig. 12.10 Right Horner syndrome. (A) In dim illumination, left pupil is larger than right pupil. (B) In brightness, both pupils constrict normally. (C) After instillation of 10% cocaine, right pupil dilates less than left pupil.

A

Horner Syndrome

C

B

Fig. 12.11 Right internal carotid artery dissection. (A) Precontrast axial T1 shows a white crescent around the right internal carotid artery at a high cervical level, indicating a blood clot dissected within the vessel wall (arrow). (B) Maximum intensity projection magnetic resonance angiography of the neck vessels shows that the lumen of the right internal carotid artery lumen is narrowed (arrowheads) compared with the normal caliber left carotid artery (arrow).

225

Horner Syndrome (Continued) Treatment • Depends on underlying lesion • Apraclonidine 0.5% for ptosis

Prognosis • Depends on underlying lesion • Even if ophthalmic manifestations do not remit, symptoms are non-disabling • If ptosis is a cosmetic blemish, can treat with daily instillation of apraclonidine 0.5% or with eyelid surgery

SECTION 12 • Pupil Disorders 226

Horner Syndrome (continued)

Fig. 12.12 Thoracic neuroblastoma causing Horner syndrome. Axial chest CT shows a large mass (arrow) in a 3 year-old child presenting with an isolated Horner syndrome.

227

Section 13 Eyelid Disorders Ptosis

230

Lid Retraction

232

Apraxia of Eyelid Opening

234

Benign Essential Blepharospasm

236

Hemifacial Spasm

238

Ptosis Key Facts • Droopy upper lid caused by innervational failure (neurogenic ptosis) or levator palpebrae superioris muscle damage (myogenic ptosis) • Causes of neurogenic ptosis: • third cranial nerve palsy • Horner syndrome • myasthenia gravis • botulism • Guillain–Barré syndrome • chronic inflammatory demyelinating polyneuropathy (CIDP) • Causes of myogenic ptosis: • congenital ptosis • senescent levator aponeurosis dehiscence • eyelid or orbital trauma or surgery • superior sino-orbital inflammation, mass, or infiltrative lesion • mitochondrial myopathy • congenital myopathy • oculopharyngeal dystrophy • myotonic dystrophy • herpes zoster • chronic contact lens wear • chronic topical steroid use

Clinical Findings

SECTION 13 • Eyelid Disorders

• Droopy upper lid with or without normal excursion • To diagnose neurogenic ptosis, first rule out eyelid or orbital signs then hunt for signs of ocular motor palsies, Horner syndrome, or myasthenia • To diagnose myogenic ptosis, rule out cranial nerve palsies, pupil abnormalities, and myasthenic weakness and hunt for eyelid masses, orbitopathy, and signs associated with congenital or heredodegenerative myopathies

Ancillary Testing • Suspected neurogenic ptosis: • topical pharmacologic testing for Horner syndrome • neck and brain imaging for intracranial lesions • lumbar puncture • nerve conduction velocities for Guillain–Barré syndrome or CIDP • electromyography and serologic testing for myasthenia gravis • Suspected myogenic ptosis: • DNA testing • muscle biopsy for mitochondrial or other myopathies • orbital imaging to rule out mass or inflammation

Differential Diagnosis • Pseudoptosis caused by: • blepharochalasis (dermatochalasis) • blepharospasm • apraxia of eyelid opening • facial contracture after facial nerve palsy • enophthalmos • eyelid or orbital deformity • supraducted eye • eyelid retraction of fellow eye • Third cranial nerve palsy: look for ductional deficits with or without mydriatic pupil • Horner syndrome: look for miosis • Myasthenia gravis: look for fatigable ptosis, ocular misalignment, orbicularis oculi, bulbar, neck, or proximal extremity muscle weakness • Guillain–Barré and CIDP: look for absent deep tendon reflexes • Botulism: look for accommodative paresis, ductional deficits, gastrointestinal symptoms • Congenital ptosis: present at birth, look for impaired lid relaxation on downgaze • Congenital myopathy, mitochondrial, oculopharyngeal, myotonic dystrophy: get history of longstanding bilateral ptosis with or without ophthalmoplegia or other neurologic signs • Levator dehiscence: look for indistinct upper eyelid crease, normal lid excursion • Orbital masses: look for resistance to retropulsion, imaging abnormalities • Contact lens wear, steroid use, previous eyelid or orbital trauma or surgery: get history


Prognosis 230

• Depends on underlying condition

Fig. 13.1 Right upper lid ptosis in a patient with myasthenia gravis.

Ptosis 231

Lid Retraction Key Facts • Upper lid is elevated so that sclera shows above superior cornea • Unilateral or bilateral • Common causes: • Graves disease • hyperalert state • psychoneurotic state • parkinsonism • dorsal midbrain (pretectal) syndrome • eyelid inflammation, trauma, or surgery with scarring (cicatricial lid retraction) • If stable and longstanding and causing exposure of the eye, surgical eyelidlowering procedures will be beneficial

Clinical Findings


• Upper lid is shortened so that sclera shows above superior cornea • Unilateral or bilateral • Graves disease: lid relaxation is delayed as eyes go into downward gaze (lid lag) • Orbital soft tissue signs of Graves ophthalmopathy present • Cicatricial lid retraction: lid fails to lower completely on downgaze (lagophthalmos) • Hyperalert and/or psychoneurotic state: eyelid retraction is bilateral • Lid lag and lagophthalmos may be present • Signs may disappear if patient can be made to relax • Parkinsonism: eyelid retraction is part of facial immobility, bradykinesia • Dorsal midbrain syndrome: eyelid retraction (Collier sign) accompanied by upgaze deficit • Light-near dissociation or completely unreactive pupils • Sometimes convergence–retraction on attempted upgaze


Suspected Graves: orbital imaging, thyroid function studies Suspected psychoneurotic state: psychiatric evaluation Suspected parkinsonism: neurologic evaluation Suspected dorsal midbrain syndrome: brain imaging

Differential Diagnosis • Suspected Graves disease: orbital imaging, thyroid function studies • Cicatricial lid retraction: history or evidence of previous trauma, surgery, or inflammation • Hyperalert state: behavioral features, medication or recreational drug use • Psychoneurotic state: behavioral features

Treatment • In longstanding and stable Graves or cicatricial lid retraction causing exposure, surgical eyelid-lowering procedures

Prognosis • Lid-lowering surgery often provides benefit

232

Fig. 13.2 Bilateral lid retraction in a patient with Graves disease.

Lid Retraction 233

Apraxia of Eyelid Opening Key Facts • Impaired or delayed ability to open eyes because of cerebral failure to recruit levator palpebrae superioris function • Manifests as bilateral prolonged eyelid closure often provoked by bright light or touch on brow • A sign of frontal lobe dysfunction (frontal release sign) • Always accompanied by other signs of parkinsonism: • Parkinson disease • progressive supranuclear palsy • multi-infarct state • multiple system atrophy • Alzheimer, Huntington, and Wilson diseases • May be mistaken for ptosis, blepharochalasis, or essential blepharospasm • Will not benefit from botulinum toxin injections unless there is also a blepharospasm component


Clinical Findings • Prolonged bilateral eyelid closure occurring spontaneously or after exposure to bright light or touch of brow • Eye opening is very slow to command • Manual attempt to open eyes only worsens eyelid closure • There are always other parkinsonian features: • facial immobility • bradykinesia • hypophonia • tremor • stance and gait instability • cognitive impairment

Ancillary Testing • Not necessary if parkinsonian state already evaluated

Differential Diagnosis • When parkinsonian features are present, there is no differential diagnosis

Treatment • May benefit from orbicularis oculi botulinum toxin injections only if there is a component of blepharospasm

Prognosis • Eyelid closure is rarely disabling—other features of the parkinsonian state are more problematic

234

A

0

0

Apraxia of Eyelid Opening

B

30 seconds

Fig. 13.3 Apraxia of eyelid opening. (A) The patient’s eyelids are closed but not in spasm. (B) Thirty seconds after being instructed to open her eyes, the eyelids gradually open. The eyelids are now in normal position.

235

Benign Essential Blepharospasm Key Facts • • • • • • • • •

Idiopathic involuntary bilateral eyelid closure May start as photophobia Often exacerbated by social encounters May be associated with contraction of other facial muscles Generally no associated neurologic or systemic illness Often misdiagnosed initially as ptosis, blepharochalasis, or dry eye Temporarily alleviated by subcutaneous botulinum toxin injections Anxiolytic medications may be adjuvants but are rarely effective alone Insight psychotherapy has been disappointing

Clinical Findings • Intermittent or constant bilateral blepharospasm • Tic-like mouthing movements sometimes present • No other pertinent abnormalities


Ancillary Testing • Not necessary


Ptosis Blepharochalasis Dry eye syndrome or other superficial keratopathies Chronic uveitis Generalized dystonia Apraxia of eyelid opening

Treatment • Botulinum toxin injections subcutaneously in a standard array on brow, eyelids, and cheek bilaterally • Anxiolytic agents may have adjuvant benefit

Prognosis • Botulinum toxin injections generally provide relief for 3–4 months • repeated injections generally effective and side effects (ptosis, exposure keratopathy, diplopia) are temporary and tolerable

236

A

B

Benign Essential Blepharospasm

C

Fig. 13.4 Blepharospasm. (A) The patient’s eyelids are in spasm bilaterally. (B) Botulinum toxin injections are given subcutaneously in the brow and eyelids. (C) One day later, the eyelid spasm has disappeared.

237

Hemifacial Spasm Key Facts • Involuntary contraction of facial muscles on one side • Generally no underlying disease, but some patients have old ipsilateral facial palsy • Believed to result from pathologic excitability of facial nerve • In some patients, surgical exploration shows compression of facial nerve at its exit from brainstem by aberrant artery • this abnormality is generally not visible with brain imaging • Botulinum toxin injections into affected side of face are usually temporarily effective • For refractory cases, suboccipital craniectomy with placement of Gelfoam between facial nerve and aberrant artery is an option

Clinical Findings • Involuntary contraction of facial muscles on one side • Upper face, including orbicular oculi, usually most prominently involved • No other pertinent findings unless pre-existing facial palsy causes ipsilateral facial weakness and ipsilateral deviation of mouth (postparetic facial contracture) and abnormal coactivation of facial muscles (facial synkinesis)


Ancillary Testing • MRI with attention to brainstem—extrinsic and intrinsic brainstem lesions may rarely cause hemifacial spasm

Treatment • Botulinum toxin injected into affected side of face is usually temporarily effective • For refractory cases, suboccipital craniectomy with placement of Gelfoam between facial nerve and aberrant artery is an option

Prognosis • Botulinum toxin injections generally relieve symptoms for 3–4 months • Craniectomy usually effective, but there is a small risk of stroke or deafness

A

238

B

Fig. 13.5 Patient with left hemifacial spasm. (A) Upper and lower facial muscles are contracted. (B) Botulinum toxin injections are given subcutaneously in the brow, eyelids, and cheek.

C

Hemifacial Spasm

Fig. 13.5, con’t (C) One day later, the facial muscle contraction has disappeared.

Fig. 13.6 Hemifacial spasm. Axial T2 MRI shows compression of the seventh cranial nerve (black arrows) by a vessel indenting its root entry zone (white arrow) in the caudal pons. (From Rahman EA et al. Am J Ophthalmol 2002; 133:854–856, with permission.)

239

Abduction deficit, sixth cranial nerve palsy, 114 Acephalic migraine, 6 Achromatopsia, 92, 93 congenital sensory nystagmus, 172, 173 Acquired binocular pendular nystagmus, 180–181 Acromegaly, 56 Acute convergence syndrome (acute comitant esotropia), 148–149 Acute disseminated encephalomyelitis, 88 Acute gaze deviation down gaze, 146–147 horizontal, 160–161 upgaze, 144–145 Adduction deficit internuclear ophthalmoplegia, 132, 133 paramedian pontine syndrome, 140, 141 third cranial nerve palsy, 110, 111 Adenoid cystic carcinoma, 119 Adie tonic pupil, 208 Adrenocorticotropin-secreting pituitary adenoma, 56 Afferent pupil defect anterior visual pathway aneurysm, 60 meningioma optic nerve sheath, 52 sphenoid, 48 monocular pendular nystagmus, 174 optic glioma, 58 optic neuritis, 24 atypical, 28 optic neuropathy posterior ischemic, 36 radiation, 64 traumatic, 62 papillitis (neuroretinitis), 30 pituitary adenoma, 56 Albinism, 172 Alcohol-related optic neuropathy, 40, 42, 43 Alzheimer disease, 92, 94, 158, 234 Amaurosis fugax, 2–3 Amblyopia, monocular pendular nystagmus, 174 Amenorrhea, 56 Amitriptyline toxicity, 200 Amyloidosis, 208 Aneurysm anterior visual pathway, 60–61 compressive optic neuropathy/ chiasmopathy, 48

third cranial nerve palsy, 110, 111, 216 unilateral ophthalmoplegia, 118 Aniridia, congenital sensory nystagmus, 172 Anisocoria Argyll Robertson pupils, 210 episodic pupil dilation, 220 Horner syndrome, 224 ophthalmoplegia bilateral, 120 unilateral, 118 physiologic (simple; benign; essential), 222–223 tectal (dorsal midbrain) pupils, 212 tonic pupil, 208 Anoxic encephalopathy, ocular bobbing, 204 Anterior ischemic optic neuropathy, 82 arteritic, 34–35 non-arteritic, 32–33 Anterior visual pathway, 49 intracranial aneurysm, 60–61 intracranial mass compression, 48–49 Anton syndrome, 88 Apraxia of eyelid opening, 234–235 ocular motor acquired (supranuclear gaze palsy), 158–159 congenital, 156–157 Argyll Robertson pupils, 210–211 Arteriosclerosis, 2, 32, 60, 64, 142 ischemic cranial nerve palsy, 110, 112, 114 Arteriosclerotic risk factors, 2, 4, 32, 38, 110 Arteriovenous fistula, 118 Arteriovenous malformation, 187 Arteritic anterior ischemic optic neuropathy, 34–35 Ataxia acute convergence syndrome, 148 dorsolateral medullary syndrome, 142 internuclear ophthalmoplegia, 132 ocular dysmetria, 202 optic, 94 paramedian thalamic/midbrain syndrome, 138 skew deviation, 134 spinocerebellar, 150 supranuclear gaze palsy (acquired ocular motor apraxia), 158 Ataxia telangiectasia, 158 Atrial fibrillation, 2, 4 Atrophic papilledema, 68 Atropinic substances, 214 Atypical optic neuritis, 28–29

Index

A

Autoimmune disorders, 28, 98, 100, 104, 178 postviral, 200

B Balint syndrome, 94 Basal encephalocele, 14, 18 Benign anisocoria, 222–223 Benign essential blepharospasm, 236–237 Benign paroxysmal vertigo, 178 Berry (saccular) aneurysm, 60, 216 Blepharospasm, benign essential, 236–237 Botulism, 230 bilateral ophthalmoplegia, 120, 122 Brain abscess, 88 Brainstem lesions acquired binocular pendular nystagmus, 180 ocular bobbing, 204 ocular dysmetria, 202 ocular flutter/opsoclonus, 200 ocular motor disorders, 132–153 square wave jerks, 198, 199 Brainstem stroke, 132, 134 acute down gaze deviation, 146 dorsal midbrain syndrome, 136 Brainstem trauma, 198 Brainstem tumor, 132, 134 Brainstem vestibulocerebellar dysfunction, 182 Branch retinal artery constriction, retinal migraine, 9 Breast cancer, 5, 78, 200 Bruit, carotid–cavernous sinus direct, 124 indirect (dural), 126

C

242

Callosal dysgenesis, 18 Carbamazepine toxicity, 144, 182 Cardiac bypass, 38 Cardiac disorders, genetic extraocular myopathies, 102 Carotid artery aneurysm, 60, 61 Carotid–cavernous sinus direct, 124–125 indirect (dural), 126–129 Cat scratch disease, 30 Cavernous hemangioma, paramedian pontine syndrome, 141 Cavernous sinus lesions bilateral ophthalmoplegia, 120, 121, 122 Horner syndrome, 224

Central retinal artery constriction, retinal migraine, 9 Cerebellar lesions, 198, 203 ocular dysmetria, 202 omnidirectional saccadic pursuit, 152 Cerebellar tumor, 132, 134 Cerebral achromatopsia, 92, 93 Cerebral blindness (retrogeniculate/cortical blindness), 88–91 Cerebral gaze disorders, 156–165 Cerebral infarct acute horizontal deviation, 160, 161 bilateral ophthalmoplegia, 120 cerebral blindness, 88, 89, 91 homonymous hemianopia, 86, 87 supranuclear gaze palsy (acquired ocular motor apraxia), 158 visual agnosia, 93 visual spatial and attentional disturbances, 94, 95 see also Stroke Cervical carotid disease dissection, 224 monocular transient visual loss (amaurosis fugax), 2, 3 Chiari malformation, 184, 185 Chiasmal glioma, 175 Chiasmal pilocytic astrocytoma (optic glioma), 58–59 Chiasmopathy, compressive, 48–49, 51, 60 Chlordecone poisoning, 200 Choroidopathy, hypertensive, 76 Chronic inflammatory demyelinating polyneuropathy, 230 Chronic progressive external ophthalmoplegia, 102 Cicatricial lid retraction, 232 Cluster headache, 224 Cocaine toxicity, 200 Collier sign, 136 Color vision loss, optic neuropathy nutritional deficiency, 42 toxic, 40 Compressive optic neuropathy/ chiasmopathy, 48–49, 51, 60 Congenital midline dysgenesis, 180 Congenital nystagmus motor, 170–171 sensory, 172–173 Congenital ocular motor apraxia, 156–157 Congenital optic nerve disorders, 12–21 Congenital ptosis, 230 Congenitally elevated optic disc, 12–13 Conjunctival congestion Graves disease, 66, 67, 100

D Dawson fingers, 27 De Morsier syndrome (corpus callosum hypoplasia), 20 Demyelination nystagmus, 182 optic nerve primary, 24 secondary, 28 paramedian pontine syndrome, 140 paramedian thalamic/midbrain syndrome, 138 tectal (dorsal midbrain) pupils, 212 Diabetes, 32, 64 cranial nerve palsy fourth, 112 sixth, 114 third, 110 maternal, optic disc hypoplasia, 20, 21 papillopathy, 82–83 pituitary adenoma, 56

Diplopia acute convergence syndrome, 148 carotid–cavernous sinus direct, 124 indirect (dural), 126 cranial nerve palsy fourth, 112 third, 216 dorsolateral medullary syndrome, 142 Graves disease, 100 internuclear ophthalmoplegia, 132 myasthenia gravis, 104, 106 orbital myositis, 98 skew deviation, 134 spasm of near reflex, 162 Dissociated migraine, 6 Doll’s head maneuver acute down gaze deviation, 146 acute horizontal gaze deviation, 160 bilateral ophthalmoplegia, 120 dorsal midbrain syndrome, 136 genetic extraocular myopathy, 102 ocular motor apraxia acquired (supranuclear gaze palsy), 158 congenital, 156 paramedian pontine syndrome, 140 Dorsal midbrain lesions, convergence– retraction nystagmus, 190 Dorsal midbrain (pretectal) syndrome, 136– 137, 139, 232 Dorsal midbrain (tectal) pupils, 212–213 Dorsolateral medullary (Wallenberg) syndrome, 142–143, 224 Double-ring sign, optic disc hypoplasia, 20, 21 Down gaze deviation, acute, 146–147 Downbeat nystagmus, 182–185 Drug adverse effects acute convergence syndrome, 148 acute upgaze deviation, 144 dilated pupils, 214–215 nystagmus, 182 ocular flutter/opsoclonus, 200 toxic optic neuropathy, 40 Drusen, congenitally elevated optic disc, 12, 13 Ductional deficits carotid–cavernous sinus direct, 124 indirect (dural), 126 cranial nerve palsy sixth, 114 third, 78–79, 110 genetic extraocular myopathy, 102, 103 Graves disease, 100, 101

Index

ophthalmoplegia bilateral, 120 unilateral, 118 orbital myositis, 98 Conjunctival injection carotid–cavernous sinus direct, 124 indirect (dural), 126, 127 Horner syndrome, 224 Connective tissue disease, 98 Contraceptive medication, 6 Convergence syndrome (acute comitant esotropia), 148–149 Convergence–retraction nystagmus, 190– 191, 212 Corpus callosum hypoplasia (de Morsier syndrome), 20 Cortical (cerebral; retrogeniculate) blindness, 88–91 Cotton wool spots arteritic anterior ischemic optic neuropathy, 34 hypertensive retinopathy, 76, 77 papilledema, 68 papillitis (neuroretinitis), 31 Cranial nerve palsies fourth nerve, 112–113 seventh nerve, 238, 239 sixth nerve, 114–115 third nerve, 110–111, 216–217 Craniopharyngioma, 48, 54–55, 172, 174 Creutzfeldt–Jakob disease, 88 Cushingoid features, 56

243

myasthenia gravis, 104, 105 ophthalmoplegia bilateral, 120, 121 internuclear, 132, 133 unilateral, 118, 119 orbital myositis, 98, 99 paramedian pontine syndrome, 140, 141 Dural carotid–cavernous sinus, 126–129 Dural sinus thrombosis, 68, 70 Dyslipidemia, 32

E

244

Embolus, 2 Hollenhorst plaque, 2, 3 paramedian thalamic/midbrain syndrome, 138 transient ischemic attack, 4 Encephalomalacia, 4 Epileptic nystagmus, 186–187 Epileptogenic occipital mass, 5 Episodic pupil dilation, 220–221 Esotropia acute comitant (acute convergence syndrome), 148–149 acute down gaze deviation, 146 dorsal midbrain syndrome, 136 idiopathic intracranial hypertension, 72 paramedian thalamic/midbrain syndrome, 138 sixth cranial nerve palsy, 114, 115 spasm of near reflex, 162 Essential anisocoria, 222–223 Ethambutol optic neuropathy, 40, 41 Exotropia dorsal midbrain syndrome, 136 internuclear ophthalmoplegia, 132 paramedian pontine syndrome, 140, 141 paramedian thalamic/midbrain syndrome, 138 pontine, 160 Extraocular muscle disorders, 98–106 nystagmus, 188–189 Extraocular muscle inflammation Graves disease, 66, 67, 100 orbital myositis, 98 Extraocular myopathies, genetic, 102–103 omnidirectional slow saccades, 150 Eyelid coloboma, 14 Eyelid congestion carotid–cavernous sinus direct, 124 indirect (dural), 126, 127 Graves disease, 100

ophthalmoplegia bilateral, 120 unilateral, 118 Eyelid disorders, 230–239 Eyelid opening apraxia, 234–235 Eyelid retraction, 232–233 dorsal midbrain syndrome, 136, 232 Graves disease, 100, 232, 233 with pharmacologically dilated pupils, 214 tectal (dorsal midbrain) pupils, 212

F Face agnosia (prosopagnosia), 92, 93 Facial synkinesis, 238 Fisher syndrome, 120, 122, 140 Focal seizure cerebral blindness, 88 transient binocular visual loss, 4 Forebrain anomalies morning glory optic disc anomaly, 18 optic disc coloboma, 14 optic disc hypoplasia, 20 Fourth cranial nerve palsy, 112–113 Frontal release sign, 234 Frontoparietal infarct, 120 acute horizontal gaze deviation, 160 supranuclear gaze palsy (acquired ocular motor apraxia), 158, 159 Fusiform aneurysm, 60

G Galactorrhea, 56 Gaze disorders acute down gaze deviation, 146–147 acute horizontal deviation, 160–161 acute upgaze deviation, 144–145 cerebral, 156–165 dorsal midbrain syndrome, 136 internuclear ophthalmoplegia, 132, 133 ocular motor apraxia acquired (supranuclear gaze palsy), 158–159 congenital, 156–157 paramedian pontine syndrome, 140, 141 paramedian thalamic/midbrain syndrome, 138, 139 ping pong gaze, 164–165 skew deviation, 134 spasm of near reflex, 162–163 sunset sign, 147 tectal (dorsal midbrain) pupils, 212 Genetic extraocular myopathy, 102–103 omnidirectional slow saccades, 150

Germinoma, 48 Giant cell arteritis, 36 Gigantism, 56 Glioblastoma multiforme, 149 Glioma, 174, 175 tectal, 213 Glycopyrrolate, 214 Goiter, 56 Gonadotropin-secreting pituitary adenoma, 56 Graves disease, 100–101, 232, 233 optic neuropathy, 66–67 Growth hormone-secreting pituitary adenoma, 56 Guillain–Barré syndrome, 208, 230

H

Index

Habit spasm (tic), acute upgaze deviation, 144 Hallucination cerebral blindness, 88 homonymous hemianopia, 86 migraine with visual aura, 6 Hard exudates papilledema, 68 papillitis (neuroretinitis), 30, 31 Head injury cranial nerve palsy fourth, 112 sixth, 114 third, 110 homonymous hemianopia, 86 internuclear ophthalmoplegia, 132 Head nodding, spasmus nutans, 176 Head tilt, fourth cranial nerve palsy, 112, 113 Headache anterior visual pathway aneurysm, 60 arteritic anterior ischemic optic neuropathy, 34 craniopharyngioma, 54 episodic pupil dilation, 220 idiopathic intracranial hypertension, 72 migraine, 4, 6 pituitary adenoma, 56 spasm of near reflex, 162 sphenoid meningioma, 48 transient ischemic attack, 4 Hearing loss with dominantly inherited optic neuropathy, 44 peripheral vestibular nystagmus, 178 Hemifacial spasm, 238–239 Hemispatial neglect syndrome, 160

Hepatic encephalopathy acute down gaze deviation, 146 cerebral blindness, 88 Hereditary cerebellar degeneration, 151 Hereditary neuropathies, tonic pupil, 208 Herpes zoster, 36, 230 Hollenhorst plaque, 2, 3 Holmes–Adie syndrome, 208 Homonymous hemianopia, 86–87 cerebral blindness, 88 focal seizure, 4, 5 migraine with visual aura, 6 visual agnosia, 92, 93 visual spatial and attentional disturbances, 94 Hormone-secreting pituitary adenoma, 56 Horner syndrome, 224–227, 230 dorsolateral medullary syndrome, 142, 143 Huntington disease, 198, 234 Hydrocephalus, 54, 58, 136, 138 acute down gaze deviation, 146, 147 papilledema, 70 tectal (dorsal midbrain) pupils, 212 Hyperalert state, 232 Hypercoagulable state, 2 Hypersolmnelence, 138 Hypertension, 2, 4, 32, 60 choroidopathy, 76 optic neuropathy, 76–77 of pregnancy, cerebral blindness, 91 retinopathy, 76, 77 Hypoglycemia, cerebral blindness, 88 Hypopituitarism anterior visual pathway aneurysm, 60 craniopharyngioma, 54 morning glory optic disc anomaly, 18 optic disc hypoplasia, 20 pituitary adenoma, 56 Hypotension, systemic, 2 ischemic optic neuropathy, 36, 38–39 transient visual loss, 4 Hypothalamus, optic glioma involvement, 58 Hypoxic-ischemic encephalopathy, 165 acute upgaze deviation, 144 cerebral blindness, 91

I Idiopathic intracranial hypertension (pseudotumor cerebri), 72–75 papilledema, 70, 72, 73, 74, 75 Impotence, 56 Inferior parietal cortex dysfunction, 94 Infiltrative optic neuropathy, 78–79

245

Infraduction defect, third cranial nerve palsy, 110, 111 Internuclear ophthalmoplegia, 132–133 one and a half syndrome, 160 skew deviation, 132, 134 Intracranial mass, compressive nerve palsy fourth cranial nerve, 112 sixth cranial nerve, 114 third cranial nerve, 110 Intracranial pressure elevation acute convergence syndrome, 148 acute down gaze deviation (sunset sign), 147 craniopharyngioma, 54 false-localizing sixth cranial nerve palsy, 114 idiopathic intracranial hypertension, 70, 72 papilledema, 68, 70 Intraocular pressure elevation carotid–cavernous sinus direct, 124, 125 indirect (dural), 126 unilateral ophthalmoplegia, 118 Iridoplegia, traumatic, 218–219 Iris atrophy, 208 Iris coloboma, 14, 15 Iris hamartoma (Lisch nodule), 58 Ischemic nerve palsy fourth cranial nerve, 112 sixth cranial nerve, 114 third cranial nerve, 110 Ischemic optic neuropathy anterior, 82 arteritic, 34–35 non-arteritic, 32–33 hypotensive, 38–39 posterior, 36–37

K Kearns–Sayre syndrome, 102, 103

L

246

Leber hereditary optic neuropathy, 46–47, 170, 172 Leukemia, 78 Linezolid optic neuropathy, 41 Lipido depression, 56 Lisch nodule (iris hamartoma), 58 Lithium toxicity, 182, 200 Lumbar spinal surgery, hypotensive ischemic optic neuropathy, 38, 39 Lung cancer, 78, 79, 200 paraneoplastic optic neuropathy, 80–81

Lupus erythematosus, 36 Lyme disease, 30 Lymphoma, 78 Lymphomatous meningitis, 78

M Macular star figure, 30, 31 Maculopathy, hypertensive, 76 Ménière disease, 178 Meningeal reactive hyperplasia, 58, 59 Meningioma optic nerve sheath, 48, 52–53 sphenoid, 48, 50–51 Meningitis atypical optic neuritis, 28 carcinomatous, 77, 78 cerebral blindness, 88 cranial nerve palsy, 110, 112, 114 lymphomatous, 78 Meningoencephalitis acute convergence syndrome, 148 cerebral blindness, 88 spasmus nutans, 176 Metabolic disorders congenital ocular motor apraxia, 156 internuclear ophthalmoplegia, 132 nystagmus, 182 omnidirectional saccadic pursuit, 152 skew deviation, 134 Metabolic encephalopathy acute convergence syndrome, 148 cerebral blindness, 88 ocular bobbing, 204 Methanol toxicity, 40 Midbrain lesions acute convergence syndrome, 148 acute down gaze deviation, 146 Midbrain syndrome, paramedian, 138–139 Midbrain tumor, 138 tectal (dorsal midbrain) pupils, 212 Midline brain malformations morning glory optic disc anomaly, 18, 19 optic disc hypoplasia, 20 Migraine acephalic, 6 dissociated, 6 episodic pupil dilation, 220 retinal (retinal vasospasm), 8–9 transient visual loss, 4 with visual aura, 6–7 Misalignment myasthenia gravis, 104 orbital myositis, 98 paramedian thalamic/midbrain syndrome, 138, 139

N Nausea/vomiting acute down gaze deviation, 146 dorsolateral medullary syndrome, 142 peripheral vestibular nystagmus, 178 Neuroblastoma, 176, 200 Horner syndrome, 224, 227 Neurodegenerative disorders internuclear ophthalmoplegia, 132 nystagmus, 182 omnidirectional slow saccades, 150 skew deviation, 134 Neurofibromatosis type 1, 58 Neurogenic ptosis, 230 Neuroleptics, oculogyric crisis, 144 Neuroretinitis (papillitis), 30–31 Nieman–Pick disease type C, 158 Non-arteritic anterior ischemic optic neuropathy, 32–33

Nutritional deficiency optic neuropathy, 42–43 Nystagmus, 168–193 congenital motor, 170–171 sensory, 172–173 convergence–retraction, 190–191, 212 downbeat, 182–185 epileptic, 186–187 of extraocular muscle dysfunction, 188–189 internuclear ophthalmoplegia, 132 paramedian pontine syndrome, 140 pendular binocular acquired, 180–181 monocular, 174–175 optic glioma, 58 spasmus nutans, 176 periodic alternating, 170, 182, 184 peripheral vestibular, 178–179 physiologic, 168–169 seasaw, 180 sidebeat, 182–185 skew deviation, 134 torsional, 212 dorsal midbrain syndrome, 136 dorsolateral medullary syndrome, 142, 143 upbeat, 182–185 voluntary, 192–193

Index

spasm of near reflex, 162, 163 vertical see Skew deviation Mitochondrial myopathy, 230 Monocular pendular nystagmus, 174–175 Monocular transient visual loss, 2–3 retinal migraine, 8 Morning glory optic disc anomaly, 18–19 Motor nystagmus, congenital, 170–171 Moya moya disease, 18 Mucomycosis, 37 Multi-infarct state, 234 Multiple sclerosis binocular pendular nystagmus, 180, 181 cerebral blindness, 88 dorsal midbrain syndrome, 136 internuclear ophthalmoplegia, 132 ocular flutter/opsoclonus, 200 omnidirectional slow saccades, 150 optic neuritis, 24, 26 paramedian pontine syndrome, 140 paramedian thalamic/midbrain syndrome, 138 sixth cranial nerve palsy, 114 skew deviation, 134 square wave jerks, 198 Multiple system atrophy, 234 Myasthenia gravis, 104–106, 112, 188, 230, 231 bilateral ophthalmoplegia, 120 Mydriatic pupil third cranial nerve palsy, 110, 216–217 traumatic iridoplegia, 218–219 Myogenic ptosis, 230 Myositis, orbital, 98–99 Myotonic dystrophy, 102, 230

O Obesity, 32 idiopathic intracranial hypertension, 72 Object agnosia, 92, 93 Occipital arteriovenous malformation, 187 Occipital epileptogenic mass, 5 Occipital lobe infarction cerebral blindness, 88, 89 visual agnosia, 93 Occipitoparietal lesion, visual spatial and attentional disturbances, 94, 95 Ocular bobbing, 204–205 Ocular dipping, 204 Ocular dysmetria, 202–203 Ocular flutter, 200–201 Ocular lateropulsion, 142 Ocular motor apraxia acquired (supranuclear gaze palsy), 94, 158–159 congenital, 156–157 Ocular motor disorders brainstem, 132–153 cranial nerve, 110–115, 118–129 Ocular myasthenia, 104

247

248

Oculogyric crisis, 144 Oculomasticatory myorhythmia, 180 Oculopalatal myoclonus, 180 Oculopharyngeal dystrophy, 102, 230 Omnidirectional saccadic pursuit, 152–153 Omnidirectional slow saccades, 150–151 One and a half syndrome acute horizontal gaze deviation, 160 paramedian pontine syndrome, 140, 141 Ophthalmic artery branch occlusion, 34 Ophthalmoplegia bilateral, 120–122 internuclear, 132–133 sphenoid meningioma, 48 unilateral, 118–119 Opsoclonus, 200–201 Optic ataxia, 94 Optic canal fracture, 62, 63 Optic disc coloboma, 14–15 form fruste, 17 Optic disc, congenital elevation, 12–13 Optic disc hemorrhage non-arteritic anterior ischemic optic neuropathy, 32, 33 papillitis (neuroretinitis), 30, 31 Optic disc hypoplasia, 20–21 Optic disc morning glory anomaly, 18–19 Optic disc neovascularization, diabetic papillopathy, 82 Optic disc pallor anterior visual pathway aneurysm, 60 craniopharyngioma, 54 optic glioma, 58 optic nerve sheath meningioma, 52 optic neuropathy arteritic anterior ischemic, 34 dominantly inherited, 44 Graves, 66 hypotensive ischemic, 38 Leber hereditary, 47 nutritional deficiency, 42, 43 toxic, 40, 41 traumatic, 62 pituitary adenoma, 56 sphenoid meningioma, 48 Optic disc swelling atypical optic neuritis, 28, 29 craniopharyngioma, 54 diabetic papillopathy, 82 monocular transient visual loss (amaurosis fugax), 2 optic glioma, 58 optic nerve sheath meningioma, 52 optic neuropathy arteritic anterior ischemic, 34 Graves, 66

hypertensive, 76, 77 hypotensive, 38 infiltrative, 78 non-arteritic anterior ischemic, 32, 33 paraneoplastic, 80 papilledema, 68 papillitis (neuroretinitis), 30, 31 sphenoid meningioma, 48 Optic glioma, 48, 58–59, 175 Optic nerve demyelination primary, 24 secondary, 28 Optic nerve disorders acquired, 24–83 congenital, 12–21 Optic nerve hypoplasia, 172, 174 Optic nerve sheath meningioma, 48, 52–53 Optic neuritis atypical, 28–29 typical, 24–27 Optic neuropathy anterior ischemic, 82 arteritic, 34–35 non-arteritic, 32–33 carotid–cavernous sinus direct, 124 indirect (dural), 126, 128 compressive, 48–49 dominantly inherited, 44–45 Graves, 66–67, 100 hypertensive, 76–77 hypotensive ischemic, 38–39 infiltrative (neoplastic), 78–79 Leber hereditary, 46–47, 170 nutritional deficiency, 42–43 nystagmus congenital sensory, 172 monocular pendular, 174 paraneoplastic, 80–81 posterior ischemic, 36–37 radiation, 54, 64–65 toxic, 40–41 traumatic, 62–63 Optic pit, 16–17 Orbicularis oculi hemifacial spasm, 238 myasthenia gravis, 104 Orbital myositis, 98–99 Organophosphate poisoning, 200 Oscillopsia dorsolateral medullary syndrome, 142 nystagmus, 182, 184 acquired binocular pendular, 180 superior oblique myokimia, 196 Ovarian cancer, 200

P

Index

Papilledema, 2, 68–71, 72 acute convergence syndrome, 148 acute down gaze deviation, 146 atrophic, 68 chronic, 68, 69, 70 craniopharyngioma, 54 false-localizing sixth cranial nerve palsy, 114 idiopathic intracranial hypertension (pseudotumor cerebri), 70, 72, 73, 74, 75 marked, 68, 69 mild, 68, 69 transient binocular visual loss, 4 Papillitis (neuroretinitis), 30–31 Papillophlebitis, 31 Paramedian pontine syndrome, 140–142 Paramedian thalamic/midbrain syndrome, 138–139 Paranasal sinus disease, 120, 122 Paraneoplastic encephalitis, 200 Paraneoplastic optic neuropathy, 80–81 Parasympathetic pharmacological agents, dilated pupils, 214 Parkinson disease, 198, 234 Parkinsonism, 232 apraxia of eyelid opening, 234 Perilymphatic fistula, 178 Periodic alternating nystagmus, 170, 182, 184 Peripapillary retinal nerve fiber layer edema Leber hereditary optic neuropathy, 46, 47 methanol toxicity, 40 Peripheral vestibular nystagmus, 178–179 Periventricular leukomalacia, 88 Pharmacologically dilated pupils, 214–215 Phenytoin toxicity, 182, 200 Physiologic anisocoria, 222–223 Physiologic nystagmus, 168–169 Pigmentary retinopathy, 102 Pilocytic astrocytoma of optic nerve/chiasm (optic glioma), 48, 58–59, 175 Pineal region tumor, 191 dorsal midbrain syndrome, 136, 137 paramedian thalamic/midbrain syndrome, 138 tectal (dorsal midbrain) pupils, 212 Ping pong gaze, 164–165 Pituitary adenoma, 48, 56–57 Pituitary apoplexy, 56, 57, 120, 122 Place (topographic) agnosia, 92, 93 Polyarteritis nodosa, 36 Polymyalgia rheumatica, 34

Pontine cavernous hemangioma, 141 Pontine glioma, 135 Pontine infarct, 204 acute horizontal gaze deviation, 160 omnidirectional slow saccades, 150 Posterior inferior cerebellar artery infarction, 142, 143 Posterior ischemic optic neuropathy, 36–37 Posterior optic radiation infarction, 88 Postviral autoimmune disorder, 200 Postviral dysautonomia, 208 Postviral encephalitis, 200 Precocious puberty, 56 Pretectal (dorsal midbrain) syndrome, 136–137, 139 Progressive multifocal leukoencephalopathy cerebral blindness, 89 visual agnosia, 92 visual spatial and attentional disturbances, 94 Progressive supranuclear palsy, 198, 234 omnidirectional slow saccades, 150 supranuclear gaze palsy (acquired ocular motor apraxia), 158 Prolactin-secreting pituitary adenoma, 56 Proptosis carotid–cavernous sinus direct, 124 indirect (dural), 126 Graves disease, 100 ophthalmoplegia bilateral, 120 unilateral, 118 optic glioma, 58 orbital myositis, 98 Prosopagnosia (face agnosia), 92, 93 Pseudopapilledema (congenitally elevated optic disc), 12–13 Pseudotumor cerebri (idiopathic intracranial hypertension), 72–75 papilledema, 70, 72, 73, 74, 75 Psychogenic blindness, 88 Psychoneurotic state, 232 Ptosis, 230–231 congenital, 230 dorsolateral medullary syndrome, 142, 143 genetic extraocular myopathy, 102 herpes zoster, 230 Horner syndrome, 224, 230 mitochondrial myopathy, 230 myasthenia gravis, 104, 106, 230, 231 myogenic, 230 neurogenic, 230

249

ophthalmoplegia bilateral, 120, 121 unilateral, 118 sphenoid meningioma, 48 third cranial nerve palsy, 110, 111, 216, 230 Pupil disorders, 208–227 Pupil light–near dissociation Argyll Robertson pupils, 210 tectal, 212 tonic, 208 Pure alexia, 92, 93

R Radiation optic neuropathy, 54, 64–65 visual agnosia, 92 visual spatial and attentional disturbances, 94 Red-eyed shunt, 124 Relapsing polychondritis, 36 Retinal artery vasospasm, 2 Retinal coloboma, 15 Retinal detachment hypertensive optic neuropathy, 76 optic pit, 16, 17 Retinal hemorrhage carotid–cavernous sinus direct, 124 indirect (dural), 126 hypertensive retinopathy, 76 papillitis (neuroretinitis), 31 Retinal migraine (retinal vasospasm), 8–9 Retinitis, 28 Retinochoroidal coloboma, 14 Retinochoroidal peripapillary atrophy morning glory optic disc anomaly, 18, 19 optic disc hypoplasia, 20, 21 Retinopathy atypical optic neuritis, 28 hypertensive, 76, 77 Retinoschisis, 16 Retrochiasmal vision disorders, 86–95 Retrogeniculate (cerebral; cortical) blindness, 88–91 Reverse ocular bobbing, 204 Reverse ocular dipping, 204 Reversible posterior leukoencephalopathy syndrome, 76 cerebral blindness, 88, 91 homonymous hemianopia, 86 Rhabdomyosarcoma, 121 Riley–Day syndrome, 208

250

S Saccadic disorders, 196–205 Saccadic pursuit internuclear ophthalmoplegia, 132 omnidirectional, 152–153 paramedian pontine syndrome, 140 skew deviation, 134 with square wave jerks, 198 Saccular (berry) aneurysm, 60, 216 Sagittal sinus thrombosis, 94 Sarcoidosis, 28, 29 Schizophrenia, 198 Scintillations focal seizure, 4, 5 migraine, 4, 6, 7 transient ischemic attack, 4 transient monocular visual loss, 2 Scopolamine patch, 214 Seasaw nystagmus, 180 Seizures acute down gaze deviation, 146 acute horizontal gaze deviation, 160 acute upgaze deviation, 144 epileptic nystagmus, 186–187 episodic pupil dilation, 220 transient binocular visual loss, 4 Sensory nystagmus, congenital, 172–173 Septum pellucidum absence, 20 Seventh cranial nerve compression, 238, 239 Sidebeat nystagmus, 182–185 Simple anisocoria, 222–223 Simultanagnosia, 94 Sino-orbital fungal infection, 36, 37 Sixth cranial nerve palsy, 114–115 Skew deviation, 134–135 acute horizontal gaze deviation, 160 dorsal midbrain syndrome, 136 dorsolateral medullary syndrome, 142 fourth cranial nerve palsy, 112, 113 internuclear ophthalmoplegia, 132 paramedian pontine syndrome, 140 Smoking, 6, 32, 46 Spasm hemifacial, 238–239 of near reflex, 162–163 Spasmus nutans, 176–177 Sphenoid meningioma, 48, 50–51 Spinocerebellar ataxias, 150 Square wave jerks, 198–199 Stroke dorsal midbrain syndrome, 136 dorsolateral medullary syndrome, 142 homonymous hemianopia, 86

T Tectal (dorsal midbrain) pupils, 212–213 Tectal glioma, 213 Temporal arteritis, 34–35 Temporal infarct, visual agnosia, 93 Teratoma, 48 Thalamic lesions acute convergence syndrome, 148 acute down gaze deviation, 146 bilateral ophthalmoplegia, 120, 122 Thalamic syndrome, paramedian, 138–139 Thalamic tumor, 138 Thallium poisoning, 200 Third cranial nerve palsy, 110–111, 230 mydriatic pupil, 216–217 Thyroid disease, 56, 66, 100 Thyrotropin-secreting pituitary adenoma, 56 Tic (habit spasm), acute upgaze deviation, 144 Tinnitus idiopathic intracranial hypertension, 72 papilledema, 68 peripheral vestibular nystagmus, 178

Toluene poisoning, 200 Tonic pupil, 208–209 Topographic (place) agnosia, 92, 93 Torsional nystagmus, 212 dorsal midbrain syndrome, 136 dorsolateral medullary syndrome, 142, 143 Torticollis, 176 Toxic disorders internuclear ophthalmoplegia, 132 omnidirectional saccadic pursuit, 152 optic neuropathy, 40–41 skew deviation, 134 Toxoplasmosis, 30 Transient ischemic attack, 2, 4 Transient visual loss, 2–9 binocular, 4–5 idiopathic intracranial hypertension, 72 monocular amaurosis fugax, 2–3 papilledema, 68 retinal migraine (retinal vasospasm), 8 Trauma brainstem, 198 carotid–cavernous sinus, 124 cerebral blindness, 88 iridoplegia, mydriatic pupil, 218–219 optic neuropathy, 62–63 otic, peripheral vestibular nystagmus, 178 sweet spot, 62 see also Head injury Tropheryma whippelii, 158, 180 Tumor cerebral blindness, 88 homonymous hemianopia, 86 infiltrative optic neuropathy, 78–79 nystagmus congenital sensory, 172 downbeat, 182 monocular pendular, 174–175 peripheral vestibular, 178 sidebeat, 182 spasmus nutans, 176 upbeat, 182 ophthalmoplegia bilateral, 120, 121 internuclear, 132 unilateral, 118, 119 paramedian pontine syndrome, 140 paramedian thalamic/midbrain syndrome, 138 sixth cranial nerve palsy, 114 skew deviation, 132, 134, 135

Index

internuclear ophthalmoplegia, 132 migraine, 6 paramedian pontine syndrome, 140 paramedian thalamic/midbrain syndrome, 138, 139 retinal migraine, 8 skew deviation, 132, 134 visual agnosia, 92 visual spatial and attentional disturbances, 94 see also Cerebral infarct Strychnine poisoning, 200 Subarachnoid hemorrhage, 148 Sunset sign, 147 Superior oblique myokimia, 196–197 Superior ophthalmic vein engorgement, carotid–cavernous sinus direct, 124, 125 indirect (dural), 126 Supraduction defect, third cranial nerve palsy, 110, 111 Supranuclear gaze palsy (acquired ocular motor apraxia), 158–159 Surface glial veils, 18 Sympathetic pharmacological agents, dilated pupils, 214 Syncope, acute upgaze deviation, 144 Synkinetic near triad, 162 Syphilis, 30, 208 Argyll Robertson pupils, 210–211

251

visual agnosia, 92 visual spatial and attentional disturbances, 94

U Upbeat nystagmus, 182–185 Upgaze deviation acute, 144–145 Graves disease, 100 Uveitis, atypical optic neuritis, 28

V Vascular malformation, 140 Vasculitis, 36, 98 Venous stasis retinopathy, 2 Ventilator aerosols, 214 Ventricular shunt malfunction, 147 Ventriculomegaly acute convergence syndrome, 148 acute down gaze deviation, 146 craniopharyngioma, 54 tectal (dorsal midbrain) pupils, 212 Vertebral artery dissection, 142 Vertigo, 178 Vestibular nystagmus, peripheral, 178–179 Vestibulo-ocular reflex, 156, 158 Viral dysautonomia, 208 Viral labyrinthitis, 178 Viral neuronitis, 178 Visual agnosia, 92–93 Visual evoked potentials nutritional deficiency optic neuropathy, 42 optic neuritis, 24 Visual field defects anterior visual pathway aneurysm, 60 cerebral blindness, 88 compressive chiasmopathy, 48 congenitally elevated optic disc, 12, 13 craniopharyngioma, 54 diabetic papillopathy, 82

252

homonymous hemianopia, 86, 87 idiopathic intracranial hypertension, 72 optic disc coloboma, 14 optic disc hypoplasia, 21 optic glioma, 58 optic nerve sheath meningioma, 52 optic neuritis, 24 atypical, 28 optic neuropathy arteritic anterior ischemic, 34 compressive, 48 dominantly inherited, 44, 45 Graves, 66 hypotensive ischemic, 38 infiltrative, 78 Leber hereditary, 46 non-arteritic anterior ischemic, 32 nutritional deficiency, 44 posterior ischemic, 36 radiation, 64 traumatic, 62 optic pit, 16 papilledema, 68, 71 papillitis (neuroretinitis), 30 sphenoid meningioma, 48 Visual inattention, 94 Visual spatial and attentional disturbances, 94–95 Voluntary nystagmus, 192–193

W Wallenberg (dorsolateral medullary) syndrome, 142–143, 224 Watershed stroke, 94 Wegener granulomatosis, 36 Wernicke encephalopathy bilateral ophthalmoplegia, 120, 122 paramedian pontine syndrome, 140 Whipple disease, 158, 180 bilateral ophthalmoplegia, 120 White-eyed shunt, 124 Wilson disease, 158, 234

Rapid Diagnosis in Ophthalmology Series- Neuro-Ophthalmology-0323044565

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